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style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1986/">1986</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1987/">1987</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1988/">1988</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1989/">1989</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1990/">1990</a><a 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href="/archive/issues/1995/">1995</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1996/">1996</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1997/">1997</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1998/">1998</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/1999/">1999</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2000/">2000</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2001/">2001</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2002/">2002</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2003/">2003</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2004/">2004</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2005/">2005</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2006/">2006</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2007/">2007</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2008/">2008</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2009/">2009</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2010/">2010</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2011/">2011</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2012/">2012</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2013/">2013</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2014/">2014</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2015/">2015</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2016/">2016</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2017/">2017</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2018/">2018</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2019/">2019</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2020/">2020</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2021/">2021</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2022/">2022</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2023/">2023</a><a class="date-selector" style="cursor:pointer;border:none;color:var(--color-black);border-radius:0.5rem;padding:0.25rem 0.5rem;font-weight:400;text-decoration:none" href="/archive/issues/2024/">2024</a></div></div></div><div class="issue__list-8JHD2"><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/A5C574EE-6FB4-4233-9D7B449365C12FB3_source.jpg?w=600" alt="Scientific American Magazine Vol 141 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/A5C574EE-6FB4-4233-9D7B449365C12FB3_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/A5C574EE-6FB4-4233-9D7B449365C12FB3_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-12-01">December 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/E99ED18E-231C-4667-8FAE157071CD3CB1_source.jpg?w=600" alt="Scientific American Magazine Vol 141 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/E99ED18E-231C-4667-8FAE157071CD3CB1_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/E99ED18E-231C-4667-8FAE157071CD3CB1_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-11-01">November 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/5CDB23DE-850A-4BD8-9D8DF6BC0646F156_source.jpg?w=600" alt="Scientific American Magazine Vol 141 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/5CDB23DE-850A-4BD8-9D8DF6BC0646F156_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/5CDB23DE-850A-4BD8-9D8DF6BC0646F156_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-10-01">October 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/DC249FB1-A275-4F5F-89B4AF074AB73603_source.jpg?w=600" alt="Scientific American Magazine Vol 141 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/DC249FB1-A275-4F5F-89B4AF074AB73603_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/DC249FB1-A275-4F5F-89B4AF074AB73603_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-09-01">September 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/BDCA0056-37B7-4050-BD0D36D5E8DEAB29_source.jpg?w=600" alt="Scientific American Magazine Vol 141 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/BDCA0056-37B7-4050-BD0D36D5E8DEAB29_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/BDCA0056-37B7-4050-BD0D36D5E8DEAB29_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-08-01">August 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C10B1426-C7CE-4579-9CD733B73303987E_source.jpg?w=600" alt="Scientific American Magazine Vol 141 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/C10B1426-C7CE-4579-9CD733B73303987E_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C10B1426-C7CE-4579-9CD733B73303987E_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-07-01">July 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/615F1EAA-C00B-41E2-BF70A66D7789D09E_source.jpg?w=600" alt="Scientific American Magazine Vol 140 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/615F1EAA-C00B-41E2-BF70A66D7789D09E_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/615F1EAA-C00B-41E2-BF70A66D7789D09E_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-06-01">June 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/3480D895-A399-4BB9-9824A62421E601A6_source.jpg?w=600" alt="Scientific American Magazine Vol 140 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/3480D895-A399-4BB9-9824A62421E601A6_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/3480D895-A399-4BB9-9824A62421E601A6_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-05-01">May 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/7684B8AD-44B6-40E9-8A280DC8A00524CC_source.jpg?w=600" alt="Scientific American Magazine Vol 140 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/7684B8AD-44B6-40E9-8A280DC8A00524CC_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/7684B8AD-44B6-40E9-8A280DC8A00524CC_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-04-01">April 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/EF7409AA-A7A5-4039-A74C985B320FF3A6_source.jpg?w=600" alt="Scientific American Magazine Vol 140 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/EF7409AA-A7A5-4039-A74C985B320FF3A6_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/EF7409AA-A7A5-4039-A74C985B320FF3A6_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-03-01">March 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/406D3E7D-4D5D-4847-85A23F86A64FAB22_source.jpg?w=600" alt="Scientific American Magazine Vol 140 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/406D3E7D-4D5D-4847-85A23F86A64FAB22_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/406D3E7D-4D5D-4847-85A23F86A64FAB22_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-02-01">February 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1929/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/1927217B-2B57-4110-BBA27C9B4689D0AB_source.jpg?w=600" alt="Scientific American Magazine Vol 140 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/1927217B-2B57-4110-BBA27C9B4689D0AB_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/1927217B-2B57-4110-BBA27C9B4689D0AB_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1929-01-01">January 1929</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/F5BF83B6-16DE-4B33-9A3A701E736E7C5F_source.jpg?w=600" alt="Scientific American Magazine Vol 139 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/F5BF83B6-16DE-4B33-9A3A701E736E7C5F_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/F5BF83B6-16DE-4B33-9A3A701E736E7C5F_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-12-01">December 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/F9EC3402-AB0A-41A5-98A46ECE7C2CE2E0_source.jpg?w=600" alt="Scientific American Magazine Vol 139 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/F9EC3402-AB0A-41A5-98A46ECE7C2CE2E0_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/F9EC3402-AB0A-41A5-98A46ECE7C2CE2E0_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-11-01">November 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/3DC61103-31DC-4889-83FB357E037B2F9C_source.jpg?w=600" alt="Scientific American Magazine Vol 139 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/3DC61103-31DC-4889-83FB357E037B2F9C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/3DC61103-31DC-4889-83FB357E037B2F9C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-10-01">October 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/424960F5-E632-4D4E-947B0EA59A07F36F_source.jpg?w=600" alt="Scientific American Magazine Vol 139 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/424960F5-E632-4D4E-947B0EA59A07F36F_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/424960F5-E632-4D4E-947B0EA59A07F36F_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-09-01">September 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/ECC50FCA-8C0E-425F-B1B808E93D34505C_source.jpg?w=600" alt="Scientific American Magazine Vol 139 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/ECC50FCA-8C0E-425F-B1B808E93D34505C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/ECC50FCA-8C0E-425F-B1B808E93D34505C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-08-01">August 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/77F6942C-3FEA-406B-BE4D071F03C99877_source.jpg?w=600" alt="Scientific American Magazine Vol 139 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/77F6942C-3FEA-406B-BE4D071F03C99877_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/77F6942C-3FEA-406B-BE4D071F03C99877_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-07-01">July 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/5BB1832F-8083-4B88-9D5BF78C6B662425_source.jpg?w=600" alt="Scientific American Magazine Vol 138 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/5BB1832F-8083-4B88-9D5BF78C6B662425_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/5BB1832F-8083-4B88-9D5BF78C6B662425_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-06-01">June 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/7E3EC5C5-D5B3-40F4-87B60873318A9D65_source.jpg?w=600" alt="Scientific American Magazine Vol 138 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/7E3EC5C5-D5B3-40F4-87B60873318A9D65_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/7E3EC5C5-D5B3-40F4-87B60873318A9D65_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-05-01">May 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B6F06DA1-1600-4178-866FFB2198E436A6_source.jpg?w=600" alt="Scientific American Magazine Vol 138 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/B6F06DA1-1600-4178-866FFB2198E436A6_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B6F06DA1-1600-4178-866FFB2198E436A6_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-04-01">April 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/D03975A7-5988-473F-A858C0D92594BAE1_source.jpg?w=600" alt="Scientific American Magazine Vol 138 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/D03975A7-5988-473F-A858C0D92594BAE1_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/D03975A7-5988-473F-A858C0D92594BAE1_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-03-01">March 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2A457525-36C7-4408-AD77657F89AB58F3_source.jpg?w=600" alt="Scientific American Magazine Vol 138 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/2A457525-36C7-4408-AD77657F89AB58F3_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2A457525-36C7-4408-AD77657F89AB58F3_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-02-01">February 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1928/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/03DD89A4-A901-4AC8-B36DA4D0A95C9704_source.jpg?w=600" alt="Scientific American Magazine Vol 138 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/03DD89A4-A901-4AC8-B36DA4D0A95C9704_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/03DD89A4-A901-4AC8-B36DA4D0A95C9704_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1928-01-01">January 1928</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1927/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/854C119B-EE75-43CF-87987931432E9480_source.jpg?w=600" alt="Scientific American Magazine Vol 137 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/854C119B-EE75-43CF-87987931432E9480_source.jpg?w=300 300w, 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loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1927-11-01">November 1927</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1927/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/8C541D12-15CD-4395-BC7E9A1EE7CF13E4_source.jpg?w=600" alt="Scientific American Magazine Vol 137 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/8C541D12-15CD-4395-BC7E9A1EE7CF13E4_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/8C541D12-15CD-4395-BC7E9A1EE7CF13E4_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1927-10-01">October 1927</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1927/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/435E89F1-D44F-47C8-BE66A3A8C52CB185_source.jpg?w=600" alt="Scientific American Magazine Vol 137 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/435E89F1-D44F-47C8-BE66A3A8C52CB185_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/435E89F1-D44F-47C8-BE66A3A8C52CB185_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1927-09-01">September 1927</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1927/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/4782398F-66E7-4893-9EE94CBBAA299048_source.jpg?w=600" alt="Scientific American Magazine Vol 137 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/4782398F-66E7-4893-9EE94CBBAA299048_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/4782398F-66E7-4893-9EE94CBBAA299048_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1927-08-01">August 1927</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1927/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/D3DA680B-98CC-48F4-B8D95A8201193980_source.jpg?w=600" alt="Scientific American Magazine Vol 137 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/D3DA680B-98CC-48F4-B8D95A8201193980_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/D3DA680B-98CC-48F4-B8D95A8201193980_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1927-07-01">July 1927</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1927/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C37E7EA9-7841-4873-8D668587ECDE7AC1_source.jpg?w=600" alt="Scientific American Magazine Vol 136 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/C37E7EA9-7841-4873-8D668587ECDE7AC1_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C37E7EA9-7841-4873-8D668587ECDE7AC1_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1927-06-01">June 1927</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1927/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/071E0F60-B2FE-4666-A00EBA6D20831CD1_source.jpg?w=600" alt="Scientific American Magazine Vol 136 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/071E0F60-B2FE-4666-A00EBA6D20831CD1_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/071E0F60-B2FE-4666-A00EBA6D20831CD1_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1927-05-01">May 1927</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1927/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/424FE904-15B4-4C93-BFB27021E94A1CC8_source.jpg?w=600" alt="Scientific American Magazine Vol 136 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/424FE904-15B4-4C93-BFB27021E94A1CC8_source.jpg?w=300 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width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1927-03-01">March 1927</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1927/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/F9814000-5F34-4812-88C0A042D2CF6F2C_source.jpg?w=600" alt="Scientific American Magazine Vol 136 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/F9814000-5F34-4812-88C0A042D2CF6F2C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/F9814000-5F34-4812-88C0A042D2CF6F2C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1927-02-01">February 1927</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1927/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/85C3435A-7B3B-4587-82A9FC425A23FC71_source.jpg?w=600" alt="Scientific American Magazine Vol 136 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/85C3435A-7B3B-4587-82A9FC425A23FC71_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/85C3435A-7B3B-4587-82A9FC425A23FC71_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1927-01-01">January 1927</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/A5D6E9EC-E2D7-417B-8632C8C2550A5A4E_source.jpg?w=600" alt="Scientific American Magazine Vol 135 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/A5D6E9EC-E2D7-417B-8632C8C2550A5A4E_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/A5D6E9EC-E2D7-417B-8632C8C2550A5A4E_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-12-01">December 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/6AB8B3E8-B560-4835-83DB505ACB2113EB_source.jpg?w=600" alt="Scientific American Magazine Vol 135 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/6AB8B3E8-B560-4835-83DB505ACB2113EB_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/6AB8B3E8-B560-4835-83DB505ACB2113EB_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-11-01">November 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/D9FEDE95-2D1E-4DA2-95743BCE92148DF0_source.jpg?w=600" alt="Scientific American Magazine Vol 135 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/D9FEDE95-2D1E-4DA2-95743BCE92148DF0_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/D9FEDE95-2D1E-4DA2-95743BCE92148DF0_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-10-01">October 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/BB1DA153-D65B-40A0-9D05250F4657275C_source.jpg?w=600" alt="Scientific American Magazine Vol 135 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/BB1DA153-D65B-40A0-9D05250F4657275C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/BB1DA153-D65B-40A0-9D05250F4657275C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-09-01">September 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/256C7668-D02A-4289-98CBA1FE4BB355AE_source.jpg?w=600" alt="Scientific American Magazine Vol 135 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/256C7668-D02A-4289-98CBA1FE4BB355AE_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/256C7668-D02A-4289-98CBA1FE4BB355AE_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-08-01">August 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/8ECF0A79-D9AB-48DB-9C922D35894AE926_source.jpg?w=600" alt="Scientific American Magazine Vol 135 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/8ECF0A79-D9AB-48DB-9C922D35894AE926_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/8ECF0A79-D9AB-48DB-9C922D35894AE926_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-07-01">July 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/850645AE-AD32-4688-9AC482ED9E94D00C_source.jpg?w=600" alt="Scientific American Magazine Vol 134 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/850645AE-AD32-4688-9AC482ED9E94D00C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/850645AE-AD32-4688-9AC482ED9E94D00C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-06-01">June 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/53F05FCE-D0AD-4179-B1881F2863F43475_source.jpg?w=600" alt="Scientific American Magazine Vol 134 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/53F05FCE-D0AD-4179-B1881F2863F43475_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/53F05FCE-D0AD-4179-B1881F2863F43475_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-05-01">May 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/21F7DC60-3741-4226-BC09D19356013EFD_source.jpg?w=600" alt="Scientific American Magazine Vol 134 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/21F7DC60-3741-4226-BC09D19356013EFD_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/21F7DC60-3741-4226-BC09D19356013EFD_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-04-01">April 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2929CBF2-0F4D-4D57-B133DB1F676B2884_source.jpg?w=600" alt="Scientific American Magazine Vol 134 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/2929CBF2-0F4D-4D57-B133DB1F676B2884_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2929CBF2-0F4D-4D57-B133DB1F676B2884_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-03-01">March 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B7E5F6AC-2947-4F6A-81A24C206BE2C0DD_source.jpg?w=600" alt="Scientific American Magazine Vol 134 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/B7E5F6AC-2947-4F6A-81A24C206BE2C0DD_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B7E5F6AC-2947-4F6A-81A24C206BE2C0DD_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-02-01">February 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1926/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/dam/m/578822b87dda8a26/original/0126Cvr.jpg?m=1715349923.668?w=600" alt="Scientific American Magazine Vol 134 Issue 1" srcSet="https://static.scientificamerican.com/dam/m/578822b87dda8a26/original/0126Cvr.jpg?m=1715349923.668?w=300 300w, https://static.scientificamerican.com/dam/m/578822b87dda8a26/original/0126Cvr.jpg?m=1715349923.668?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1926-01-01">January 1926</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/9A58C3C1-EE54-4502-A0A2AF84729550FB_source.jpg?w=600" alt="Scientific American Magazine Vol 133 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/9A58C3C1-EE54-4502-A0A2AF84729550FB_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/9A58C3C1-EE54-4502-A0A2AF84729550FB_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-12-01">December 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/50AE6372-6873-4335-B125B7DDFB1119BD_source.jpg?w=600" alt="Scientific American Magazine Vol 133 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/50AE6372-6873-4335-B125B7DDFB1119BD_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/50AE6372-6873-4335-B125B7DDFB1119BD_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-11-01">November 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/497B9189-A956-41BE-B911C38521C98056_source.jpg?w=600" alt="Scientific American Magazine Vol 133 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/497B9189-A956-41BE-B911C38521C98056_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/497B9189-A956-41BE-B911C38521C98056_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-10-01">October 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B69A232A-C891-49AD-879B4A7C7DE4C854_source.jpg?w=600" alt="Scientific American Magazine Vol 133 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/B69A232A-C891-49AD-879B4A7C7DE4C854_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B69A232A-C891-49AD-879B4A7C7DE4C854_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-09-01">September 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/47D99203-A66F-4880-9D228E5BFE6CC0A1_source.jpg?w=600" alt="Scientific American Magazine Vol 133 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/47D99203-A66F-4880-9D228E5BFE6CC0A1_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/47D99203-A66F-4880-9D228E5BFE6CC0A1_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-08-01">August 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/0C12714B-0177-4D92-ADDAA370D6C5926E_source.jpg?w=600" alt="Scientific American Magazine Vol 133 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/0C12714B-0177-4D92-ADDAA370D6C5926E_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/0C12714B-0177-4D92-ADDAA370D6C5926E_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-07-01">July 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/12453F07-AF6A-4B97-8BED48B975668A36_source.jpg?w=600" alt="Scientific American Magazine Vol 132 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/12453F07-AF6A-4B97-8BED48B975668A36_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/12453F07-AF6A-4B97-8BED48B975668A36_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-06-01">June 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/30FC3C1D-EC35-48B5-BAF4BF70CD96315B_source.jpg?w=600" alt="Scientific American Magazine Vol 132 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/30FC3C1D-EC35-48B5-BAF4BF70CD96315B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/30FC3C1D-EC35-48B5-BAF4BF70CD96315B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-05-01">May 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/A0222165-3985-4DAE-9E0B9F93C4781D71_source.jpg?w=600" alt="Scientific American Magazine Vol 132 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/A0222165-3985-4DAE-9E0B9F93C4781D71_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/A0222165-3985-4DAE-9E0B9F93C4781D71_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-04-01">April 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/EE51DB6B-4CBE-4445-AAB083E30ED48DC8_source.jpg?w=600" alt="Scientific American Magazine Vol 132 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/EE51DB6B-4CBE-4445-AAB083E30ED48DC8_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/EE51DB6B-4CBE-4445-AAB083E30ED48DC8_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-03-01">March 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/991E1449-8154-494B-9A409D2C832A5EDD_source.jpg?w=600" alt="Scientific American Magazine Vol 132 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/991E1449-8154-494B-9A409D2C832A5EDD_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/991E1449-8154-494B-9A409D2C832A5EDD_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-02-01">February 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1925/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/31B02DAA-566B-4B50-9F163D074AAD5202_source.jpg?w=600" alt="Scientific American Magazine Vol 132 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/31B02DAA-566B-4B50-9F163D074AAD5202_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/31B02DAA-566B-4B50-9F163D074AAD5202_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1925-01-01">January 1925</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1924/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/3ADE29AD-BE21-4DA4-A29FEDA49DCC9F7A_source.jpg?w=600" alt="Scientific American Magazine Vol 131 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/3ADE29AD-BE21-4DA4-A29FEDA49DCC9F7A_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/3ADE29AD-BE21-4DA4-A29FEDA49DCC9F7A_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1924-12-01">December 1924</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1924/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/4AF2E32A-88C5-48C2-B290117408783ECB_source.jpg?w=600" alt="Scientific American Magazine Vol 131 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/4AF2E32A-88C5-48C2-B290117408783ECB_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/4AF2E32A-88C5-48C2-B290117408783ECB_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1924-11-01">November 1924</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1924/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/931AD251-F5FA-4C86-AA9DD235BC4D75C6_source.jpg?w=600" alt="Scientific American Magazine Vol 131 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/931AD251-F5FA-4C86-AA9DD235BC4D75C6_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/931AD251-F5FA-4C86-AA9DD235BC4D75C6_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1924-10-01">October 1924</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1924/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" 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loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1924-06-01">June 1924</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1924/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/dam/m/194f44b06b3b9cfb/original/0524Cvr.jpg?m=1715349797.011?w=600" alt="Scientific American Magazine Vol 130 Issue 5" srcSet="https://static.scientificamerican.com/dam/m/194f44b06b3b9cfb/original/0524Cvr.jpg?m=1715349797.011?w=300 300w, https://static.scientificamerican.com/dam/m/194f44b06b3b9cfb/original/0524Cvr.jpg?m=1715349797.011?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1924-05-01">May 1924</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1924/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/DB4F2A3A-C154-4CDE-AAFB02C9A5D681AE_source.jpg?w=600" alt="Scientific American Magazine Vol 130 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/DB4F2A3A-C154-4CDE-AAFB02C9A5D681AE_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/DB4F2A3A-C154-4CDE-AAFB02C9A5D681AE_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1924-04-01">April 1924</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1924/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/A97BB26D-7A82-4A58-A4144D0F2A76FC6C_source.jpg?w=600" alt="Scientific American Magazine Vol 130 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/A97BB26D-7A82-4A58-A4144D0F2A76FC6C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/A97BB26D-7A82-4A58-A4144D0F2A76FC6C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1924-03-01">March 1924</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1924/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img 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src="https://static.scientificamerican.com/sciam/cache/file/C52C0414-FA72-449D-A5A162C5B1077D46_source.jpg?w=600" alt="Scientific American Magazine Vol 130 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/C52C0414-FA72-449D-A5A162C5B1077D46_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C52C0414-FA72-449D-A5A162C5B1077D46_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1924-01-01">January 1924</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1923/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/AA048724-D5C1-438E-9C0FFF14A66F7A77_source.jpg?w=600" alt="Scientific American 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loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1923-09-01">September 1923</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1923/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/465D20CD-2F09-47CC-883D05D3026555FD_source.jpg?w=600" alt="Scientific American Magazine Vol 129 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/465D20CD-2F09-47CC-883D05D3026555FD_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/465D20CD-2F09-47CC-883D05D3026555FD_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1923-08-01">August 1923</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1923/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/DD4912A3-2BFF-41EE-81AC3CAB8BB2753D_source.jpg?w=600" alt="Scientific American Magazine Vol 129 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/DD4912A3-2BFF-41EE-81AC3CAB8BB2753D_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/DD4912A3-2BFF-41EE-81AC3CAB8BB2753D_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1923-07-01">July 1923</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1923/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/A1D96282-F60C-406F-9B3213F396609D2B_source.jpg?w=600" alt="Scientific American Magazine Vol 128 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/A1D96282-F60C-406F-9B3213F396609D2B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/A1D96282-F60C-406F-9B3213F396609D2B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1923-06-01">June 1923</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1923/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/E49660CF-7E5E-4FA9-905D42B66EF5FC09_source.jpg?w=600" alt="Scientific American Magazine Vol 128 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/E49660CF-7E5E-4FA9-905D42B66EF5FC09_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/E49660CF-7E5E-4FA9-905D42B66EF5FC09_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1923-05-01">May 1923</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1923/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/FADE9BBF-A035-4516-B702BFFE8AD01BE1_source.jpg?w=600" alt="Scientific American Magazine Vol 128 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/FADE9BBF-A035-4516-B702BFFE8AD01BE1_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/FADE9BBF-A035-4516-B702BFFE8AD01BE1_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1923-04-01">April 1923</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1923/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C26F2202-F379-4E92-96EDEB422B2D6A31_source.jpg?w=600" alt="Scientific American Magazine Vol 128 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/C26F2202-F379-4E92-96EDEB422B2D6A31_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C26F2202-F379-4E92-96EDEB422B2D6A31_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1923-03-01">March 1923</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1923/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/DBC51496-4B28-4CDD-8B7ABE6FB3458DC5_source.jpg?w=600" alt="Scientific American Magazine Vol 128 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/DBC51496-4B28-4CDD-8B7ABE6FB3458DC5_source.jpg?w=300 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width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1923-01-01">January 1923</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/E7C692B9-0C28-4FBB-85B0F2DC1990D910_source.jpg?w=600" alt="Scientific American Magazine Vol 127 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/E7C692B9-0C28-4FBB-85B0F2DC1990D910_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/E7C692B9-0C28-4FBB-85B0F2DC1990D910_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-12-01">December 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B9269144-3FF5-4D99-B99B901B95CE2D32_source.jpg?w=600" alt="Scientific American Magazine Vol 127 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/B9269144-3FF5-4D99-B99B901B95CE2D32_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B9269144-3FF5-4D99-B99B901B95CE2D32_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-11-01">November 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/9F023837-6B80-4F75-8359B9E5C91B3052_source.jpg?w=600" alt="Scientific American Magazine Vol 127 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/9F023837-6B80-4F75-8359B9E5C91B3052_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/9F023837-6B80-4F75-8359B9E5C91B3052_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-10-01">October 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/09-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/5BCF9F5E-A58A-4850-B4EA56D5BD1D6CDE_source.jpg?w=600" alt="Scientific American Magazine Vol 127 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/5BCF9F5E-A58A-4850-B4EA56D5BD1D6CDE_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/5BCF9F5E-A58A-4850-B4EA56D5BD1D6CDE_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-09-01">September 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/08-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/E01CC3C8-18A4-476F-BD3978697EEF01FA_source.jpg?w=600" alt="Scientific American Magazine Vol 127 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/E01CC3C8-18A4-476F-BD3978697EEF01FA_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/E01CC3C8-18A4-476F-BD3978697EEF01FA_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-08-01">August 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/07-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B744CAA8-306C-44E0-AA1C28E96FDE09BB_source.jpg?w=600" alt="Scientific American Magazine Vol 127 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/B744CAA8-306C-44E0-AA1C28E96FDE09BB_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B744CAA8-306C-44E0-AA1C28E96FDE09BB_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-07-01">July 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/06-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/15EE10F5-F679-4B66-BE092E64094FA83A_source.jpg?w=600" alt="Scientific American Magazine Vol 126 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/15EE10F5-F679-4B66-BE092E64094FA83A_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/15EE10F5-F679-4B66-BE092E64094FA83A_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-06-01">June 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/05-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/9EB6E397-8A7F-4C31-B0E928640E53B61B_source.jpg?w=600" alt="Scientific American Magazine Vol 126 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/9EB6E397-8A7F-4C31-B0E928640E53B61B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/9EB6E397-8A7F-4C31-B0E928640E53B61B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-05-01">May 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/04-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/ED5FFD00-CB62-45FB-8CCF638CF4EE80A4_source.jpg?w=600" alt="Scientific American Magazine Vol 126 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/ED5FFD00-CB62-45FB-8CCF638CF4EE80A4_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/ED5FFD00-CB62-45FB-8CCF638CF4EE80A4_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-04-01">April 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/03-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/F3EF8A92-CE17-4445-B7F71DBA0DDBB43C_source.jpg?w=600" alt="Scientific American Magazine Vol 126 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/F3EF8A92-CE17-4445-B7F71DBA0DDBB43C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/F3EF8A92-CE17-4445-B7F71DBA0DDBB43C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-03-01">March 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/02-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/DD71FB92-56B7-4B2B-BF33143FA1208D32_source.jpg?w=600" alt="Scientific American Magazine Vol 126 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/DD71FB92-56B7-4B2B-BF33143FA1208D32_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/DD71FB92-56B7-4B2B-BF33143FA1208D32_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-02-01">February 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1922/01-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/9698CD68-F01B-4EC8-8EEDBAB604BEDDE1_source.jpg?w=600" alt="Scientific American Magazine Vol 126 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/9698CD68-F01B-4EC8-8EEDBAB604BEDDE1_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/9698CD68-F01B-4EC8-8EEDBAB604BEDDE1_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1922-01-01">January 1922</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/12-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/EB620ADD-DBA5-4C9C-A969FFB7D696E458_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 18" srcSet="https://static.scientificamerican.com/sciam/cache/file/EB620ADD-DBA5-4C9C-A969FFB7D696E458_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/EB620ADD-DBA5-4C9C-A969FFB7D696E458_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-12-01">December 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/11-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/89C6A3FB-8746-4166-AE14675E28CBC173_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 17" srcSet="https://static.scientificamerican.com/sciam/cache/file/89C6A3FB-8746-4166-AE14675E28CBC173_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/89C6A3FB-8746-4166-AE14675E28CBC173_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-11-01">November 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/10-15/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/409C00A8-A9AC-4029-B03F85ED2F17CBB4_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 16" 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https://static.scientificamerican.com/sciam/cache/file/F5A81EBD-13F9-474F-AB52953CC40DE74C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-10-08">October 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/10-01/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/D33B1EC9-D19B-4F4B-B4FB678FB651BD78_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 14" srcSet="https://static.scientificamerican.com/sciam/cache/file/D33B1EC9-D19B-4F4B-B4FB678FB651BD78_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/D33B1EC9-D19B-4F4B-B4FB678FB651BD78_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-10-01">October 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/09-24/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/A47822BA-3190-4836-AF52A3577B65B865_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 13" srcSet="https://static.scientificamerican.com/sciam/cache/file/A47822BA-3190-4836-AF52A3577B65B865_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/A47822BA-3190-4836-AF52A3577B65B865_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-09-24">September 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/09-17/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/EF7AC39A-7EAA-4346-BABE20FA9EC43242_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 12" srcSet="https://static.scientificamerican.com/sciam/cache/file/EF7AC39A-7EAA-4346-BABE20FA9EC43242_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/EF7AC39A-7EAA-4346-BABE20FA9EC43242_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-09-17">September 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/09-10/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/97F51ACD-D924-4E57-A323E9E6192845CF_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 11" srcSet="https://static.scientificamerican.com/sciam/cache/file/97F51ACD-D924-4E57-A323E9E6192845CF_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/97F51ACD-D924-4E57-A323E9E6192845CF_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-09-10">September 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/09-03/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/5AAC2A75-E1BA-4395-8D3B8384BCB4F4A3_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 10" srcSet="https://static.scientificamerican.com/sciam/cache/file/5AAC2A75-E1BA-4395-8D3B8384BCB4F4A3_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/5AAC2A75-E1BA-4395-8D3B8384BCB4F4A3_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-09-03">September 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/08-27/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/065E811D-6DC2-42A6-B163B4406488A939_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 9" srcSet="https://static.scientificamerican.com/sciam/cache/file/065E811D-6DC2-42A6-B163B4406488A939_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/065E811D-6DC2-42A6-B163B4406488A939_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-08-27">August 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/08-20/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/F2464D13-CAC3-4765-BCFE45F884A9267C_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 8" srcSet="https://static.scientificamerican.com/sciam/cache/file/F2464D13-CAC3-4765-BCFE45F884A9267C_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/F2464D13-CAC3-4765-BCFE45F884A9267C_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-08-20">August 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/08-13/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C50FF2FD-9C77-4733-80F813212C554048_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 7" srcSet="https://static.scientificamerican.com/sciam/cache/file/C50FF2FD-9C77-4733-80F813212C554048_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C50FF2FD-9C77-4733-80F813212C554048_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-08-13">August 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/08-06/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/35B83037-D8F3-40B7-B3D15705F774347D_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 6" srcSet="https://static.scientificamerican.com/sciam/cache/file/35B83037-D8F3-40B7-B3D15705F774347D_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/35B83037-D8F3-40B7-B3D15705F774347D_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-08-06">August 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/07-30/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/8EFE9483-5974-4905-B9687AFC1C69B98F_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/8EFE9483-5974-4905-B9687AFC1C69B98F_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/8EFE9483-5974-4905-B9687AFC1C69B98F_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-07-30">July 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/07-23/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/B3E3634E-292A-4E19-91E4091804824D9F_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/B3E3634E-292A-4E19-91E4091804824D9F_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/B3E3634E-292A-4E19-91E4091804824D9F_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-07-23">July 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/07-16/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/E2507FA4-9F0E-4ECC-A45658A4D91AE64E_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 3" srcSet="https://static.scientificamerican.com/sciam/cache/file/E2507FA4-9F0E-4ECC-A45658A4D91AE64E_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/E2507FA4-9F0E-4ECC-A45658A4D91AE64E_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-07-16">July 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/07-09/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/FA4AC10B-2B67-4F56-8322FB65D50363FA_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 2" srcSet="https://static.scientificamerican.com/sciam/cache/file/FA4AC10B-2B67-4F56-8322FB65D50363FA_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/FA4AC10B-2B67-4F56-8322FB65D50363FA_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-07-09">July 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/07-02/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/35CEE885-3799-4604-8C9CC1C5E906AFC3_source.jpg?w=600" alt="Scientific American Magazine Vol 125 Issue 1" srcSet="https://static.scientificamerican.com/sciam/cache/file/35CEE885-3799-4604-8C9CC1C5E906AFC3_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/35CEE885-3799-4604-8C9CC1C5E906AFC3_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-07-02">July 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/06-25/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/E6BFDC2D-9907-41F3-BEC3BFDA3F30B612_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 26" srcSet="https://static.scientificamerican.com/sciam/cache/file/E6BFDC2D-9907-41F3-BEC3BFDA3F30B612_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/E6BFDC2D-9907-41F3-BEC3BFDA3F30B612_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-06-25">June 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/06-18/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/20A04566-DFF3-4E8B-BC4FEA76CC42923A_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 25" srcSet="https://static.scientificamerican.com/sciam/cache/file/20A04566-DFF3-4E8B-BC4FEA76CC42923A_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/20A04566-DFF3-4E8B-BC4FEA76CC42923A_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-06-18">June 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/06-11/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/62B95575-3AAA-417D-83C771E4CADCC35B_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 24" srcSet="https://static.scientificamerican.com/sciam/cache/file/62B95575-3AAA-417D-83C771E4CADCC35B_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/62B95575-3AAA-417D-83C771E4CADCC35B_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-06-11">June 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/06-04/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/F0A1D78F-CA2C-48CE-B51A2A079D75EFCE_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 23" srcSet="https://static.scientificamerican.com/sciam/cache/file/F0A1D78F-CA2C-48CE-B51A2A079D75EFCE_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/F0A1D78F-CA2C-48CE-B51A2A079D75EFCE_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-06-04">June 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/05-28/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/16A78AE6-50E4-494A-86EFBA9A9F49CF97_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 22" srcSet="https://static.scientificamerican.com/sciam/cache/file/16A78AE6-50E4-494A-86EFBA9A9F49CF97_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/16A78AE6-50E4-494A-86EFBA9A9F49CF97_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-05-28">May 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/05-21/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/DCF07DBB-0A18-4EEF-A983AA828A55C1F6_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 21" srcSet="https://static.scientificamerican.com/sciam/cache/file/DCF07DBB-0A18-4EEF-A983AA828A55C1F6_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/DCF07DBB-0A18-4EEF-A983AA828A55C1F6_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-05-21">May 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/05-14/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/3B8C2611-DD0D-43A9-83FD115D3B9FCE88_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 20" srcSet="https://static.scientificamerican.com/sciam/cache/file/3B8C2611-DD0D-43A9-83FD115D3B9FCE88_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/3B8C2611-DD0D-43A9-83FD115D3B9FCE88_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-05-14">May 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/05-07/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/055557B4-1E1C-4FD9-9457E63C2F604625_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 19" srcSet="https://static.scientificamerican.com/sciam/cache/file/055557B4-1E1C-4FD9-9457E63C2F604625_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/055557B4-1E1C-4FD9-9457E63C2F604625_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-05-07">May 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/04-30/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/E0859623-297E-4649-9918FFDA652225B8_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 18" srcSet="https://static.scientificamerican.com/sciam/cache/file/E0859623-297E-4649-9918FFDA652225B8_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/E0859623-297E-4649-9918FFDA652225B8_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-04-30">April 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/04-23/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/9A65CD20-0455-48E7-831CD96D589EA211_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 17" 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loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-04-09">April 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/04-02/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/0989495D-6986-4651-AE399A43C15EBC14_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 14" srcSet="https://static.scientificamerican.com/sciam/cache/file/0989495D-6986-4651-AE399A43C15EBC14_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/0989495D-6986-4651-AE399A43C15EBC14_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-04-02">April 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/03-26/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/96F40741-1D1A-4728-A620D583AC5D2021_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 13" srcSet="https://static.scientificamerican.com/sciam/cache/file/96F40741-1D1A-4728-A620D583AC5D2021_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/96F40741-1D1A-4728-A620D583AC5D2021_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-03-26">March 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/03-19/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/8934D361-7A91-4BBE-B9DD12C9823CC9BC_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 12" srcSet="https://static.scientificamerican.com/sciam/cache/file/8934D361-7A91-4BBE-B9DD12C9823CC9BC_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/8934D361-7A91-4BBE-B9DD12C9823CC9BC_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-03-19">March 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/03-12/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img 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loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-02-05">February 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/01-29/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/255C2F5E-1AF8-4AC5-85F175CA69D111FC_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/255C2F5E-1AF8-4AC5-85F175CA69D111FC_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/255C2F5E-1AF8-4AC5-85F175CA69D111FC_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-01-29">January 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1921/01-22/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/2131D12C-5287-44F2-A1FCC3BC87502B57_source.jpg?w=600" alt="Scientific American Magazine Vol 124 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/2131D12C-5287-44F2-A1FCC3BC87502B57_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/2131D12C-5287-44F2-A1FCC3BC87502B57_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1921-01-22">January 1921</time></div></div></div></a></div><div class="list__item--tR3J"><a 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American</h3><div class="issue__date-ozuG1"><time dateTime="1920-11-27">November 1920</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1920/11-20/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/C5D381BA-E69C-498E-999C295F0E3B5A47_source.jpg?w=600" alt="Scientific American Magazine Vol 123 Issue 21" srcSet="https://static.scientificamerican.com/sciam/cache/file/C5D381BA-E69C-498E-999C295F0E3B5A47_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/C5D381BA-E69C-498E-999C295F0E3B5A47_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1920-11-20">November 1920</time></div></div></div></a></div><div 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class="issue__date-ozuG1"><time dateTime="1920-09-25">September 1920</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1920/09-18/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/29D5BC2F-0A2A-4D78-897A731867C19AF7_source.jpg?w=600" alt="Scientific American Magazine Vol 123 Issue 12" srcSet="https://static.scientificamerican.com/sciam/cache/file/29D5BC2F-0A2A-4D78-897A731867C19AF7_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/29D5BC2F-0A2A-4D78-897A731867C19AF7_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1920-09-18">September 1920</time></div></div></div></a></div><div class="list__item--tR3J"><a 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width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1920-08-07">August 1920</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1920/07-31/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/FC3577D1-DE7A-4A30-99D64CD344C12DE8_source.jpg?w=600" alt="Scientific American Magazine Vol 123 Issue 5" srcSet="https://static.scientificamerican.com/sciam/cache/file/FC3577D1-DE7A-4A30-99D64CD344C12DE8_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/FC3577D1-DE7A-4A30-99D64CD344C12DE8_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1920-07-31">July 1920</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1920/07-24/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/9F04E9A4-7BA0-4D64-B4D03C48FEBFB18E_source.jpg?w=600" alt="Scientific American Magazine Vol 123 Issue 4" srcSet="https://static.scientificamerican.com/sciam/cache/file/9F04E9A4-7BA0-4D64-B4D03C48FEBFB18E_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/9F04E9A4-7BA0-4D64-B4D03C48FEBFB18E_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1920-07-24">July 1920</time></div></div></div></a></div><div class="list__item--tR3J"><a 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width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1920-06-12">June 1920</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1920/06-05/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/90CBCC43-EAD3-4E00-813CDBBF5B483BE1_source.jpg?w=600" alt="Scientific American Magazine Vol 122 Issue 23" srcSet="https://static.scientificamerican.com/sciam/cache/file/90CBCC43-EAD3-4E00-813CDBBF5B483BE1_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/90CBCC43-EAD3-4E00-813CDBBF5B483BE1_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div 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width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div class="issue__date-ozuG1"><time dateTime="1920-02-21">February 1920</time></div></div></div></a></div><div class="list__item--tR3J"><a class="issue__link-3e-qg" href="/issue/sa/1920/02-14/"><div class="issue-VnvuN"><div><div><figure class="issueImageContainer-WnIB2"><img class="issue__cover__image-35p5E" src="https://static.scientificamerican.com/sciam/cache/file/D4FA39C9-4013-40E2-86EF611F411E8D96_source.jpg?w=600" alt="Scientific American Magazine Vol 122 Issue 7" srcSet="https://static.scientificamerican.com/sciam/cache/file/D4FA39C9-4013-40E2-86EF611F411E8D96_source.jpg?w=300 300w, https://static.scientificamerican.com/sciam/cache/file/D4FA39C9-4013-40E2-86EF611F411E8D96_source.jpg?w=600 600w" sizes="300px" width="300" loading="lazy"/></figure></div></div><div class="issue__info-Wrv5W"><h3 class="issue__title-rRMdq">Scientific American</h3><div 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