<div class="description">
General view of assorted equipment and apparatus in the Constant Humidity Room at the the U.S. Department of Agriculture's Fertilizer Machinery Laboratory located at the Arlington Experimental Farm in Rosslyn [Arlington], Virginia. Various pieces of equipment have been labelled with letters to create an identification key. Per the key, the equipment is identified as follows: C) Receiving tray; D) Fertilizer distributor; E) Fertilizer drawer; F) Hygrothermograph; G) Revolution or speed counter; H) Dust curtain. Established by an act of Congress in April 1900, Arlington Farm served as the main field laboratory for the Bureau of Soils, U.S. Department of Agriculture, until 1941.</div>
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<ul><li><a rel="nofollow" class="external text" href="https://digital.sciencehistory.org/works/q237hr95t">Record in source catalog</a></li>
<li>DPLA identifier: <a rel="nofollow" class="external text" href="https://dp.la/item/ace9b372e06ad28710d8c0e164a03513">ace9b372e06ad28710d8c0e164a03513</a></li>
<li>Science History Institute identifier: padig:SHI-q237hr95t</li></ul></span>