<a href="https://en.wikipedia.org/wiki/Bertha_Lamme" class="extiw" title="en:Bertha Lamme">Bertha Lamme</a> (1869–1943), American electrical engineer, at work at <a href="https://en.wikipedia.org/wiki/Westinghouse_Electric_%26_Manufacturing_Company" class="extiw" title="en:Westinghouse Electric &amp; Manufacturing Company">Westinghouse Electric &amp; Manufacturing Company</a>, Pittsburgh.
Unknown author<span style="display: none;">Unknown author</span>, marked <i>W. C.Harris</i>
Dorothy Boyer, via <a rel="nofollow" class="external text" href="https://www.heinzhistorycenter.org/blog/collection-spotlight/bertha-lamme-engineer">heinzhistorycenter.org</a>