Colours help the working of steam, 55. Cycle, gearing of, 439. Cylinder, hydraulic press, _363_; steam, _49_. Danes, 382. Dead point, 47. De Brouwer stoker, 401. Detector in Chubb lock, 436; Yale lock, _436_, _437_. Yellow spot, in eye, 251. Spring balance for watches, 425.