<div class="description">
This 1901 advertisement for the British branch of the Welsbach Incandescent Gas Light Company features an owl swooping through the dark into the light of a gas mantle streetlight. The owl complains that the light makes night and day alike. It is an interesting precursor to later ecological concerns about the impact of light pollution upon nocturnal animals. It also emphasizes the brightness and efficiency of gas usage as a selling point for incandescent lamps. In the 1880s, Austrian chemist Carl Auer von Welsbach (1858-1929) created fabric impregnated with thorium and cerium, which glowed incandescently when heated by burning gas. Mantels for gas lamps were the first industrial product to use rare earth elements, and led to an international trade in rare earth ores, especially monazite. Welsbach managed firms around the world that sold gas lamps for lighting streets, homes and businesses, which shaped the visual landscapes that millions of people inhabited from the 1890s into the 1930s. In the United States, the Welsbach Incandescent Gas Lighting Company had offices on Walnut Street in Philadelphia, and a factory on the Delaware River at Gloucester, New Jersey. Many of the factory workers were women, who sewed the fabric mantels and packed the mantels into packages for sale across the country.</div>
1901-Sep-14
This file was contributed to Wikimedia Commons by <a href="https://en.wikipedia.org/wiki/en:Science_History_Institute" class="extiw" title="w:en:Science History Institute"><span title="library, museum, and archive in Philadelphia, United States">Science History Institute</span></a> as part of a cooperation project. The donation was facilitated by the <a href="https://en.wikipedia.org/wiki/Digital_Public_Library_of_America" class="extiw" title="w:Digital Public Library of America">Digital Public Library of America</a>, via its partner PA Digital.<span style="text-align:left">
<ul><li><a rel="nofollow" class="external text" href="https://digital.sciencehistory.org/works/6etlqg5">Record in source catalog</a></li>
<li>DPLA identifier: <a rel="nofollow" class="external text" href="https://dp.la/item/7acc0814dd21568b0ff67608b868e798">7acc0814dd21568b0ff67608b868e798</a></li>
<li>Science History Institute identifier: padig:SHI-6etlqg5</li></ul></span>