nds of a cross- “The way that incandescent lamps are made is very bar pivoted at, and extending across, the center of simple,” an electrician said recently. ‘*‘ There are dif- | the valve; the other end of each spring has anadjust- ferent ways of preparing the filaments, which are 'ing screw bolt… … be lifted. The lever is then swung down, when the Manufacturers doing a large business have kettles WETHERILL’S BALANCED SLIDE VALVE. pinion engages with both racks, the standard rack holding several thousand pounds, The ingredients of forming a fulcrum and the plate being raised; the slide…
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