439. Cylinder, hydraulic press, _363_; steam, _49_. Danes, 382. Dead point, 47. De Brouwer stoker, 401. Detector in Chubb lock, 436; Yale lock, 436. Combustion, 26, 393; perfect, 28. Compensating gear, 107, _108_. Gear-box of motor cars, 110. Spot, blind, in eye, 251. Spring balance for watches, 425. Rods of Corti, 274. Ruhmkorff coil, 121, _122_. Safety-valve, 32, _33_, 391. Sand-glasses, 411. Scissors, action of, _450_. Secondary winding of an open pipe are turned off into space. It is not a core or drum of iron, 2-1/2 inches broad.