Twentieth century handbook for steam engineers and electricians, with questions and answers; a practical nontechnical treatise .. (1916)
Swingle, Calvin F. (Calvin Franklin), b. 1846 · Chicago, F.J. Drake & company · leaf 759
bined steam and gas engineindicator, and is supplied with two sizes of pistons as in thecase of the indicator just mentioned. The spring is placedoutside of the indicator cylinder in order that the hot gasesfrom the engine will not affect the temper of the spring,and thereby change the scale. Fig… … Fig. 309 for a perfectly true vertical motion of the pencil, and fur-ther provides rigidity and tends to reduce vibration. This indicator is made with the regular i/o-inch areapiston and cylinder for steam, and is furnished with asecondary and longer piston of 14-inch area which operatesin the…