Dead point, 47. De Brouwer stoker, 401. Detector in Chubb lock, 436; Yale lock, _436_, _437_. Yellow spot, in eye, 251; yellow, in eye, 251; yellow, 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 dynamo, 161, _172_. Bunsen burner, 409. Burning-glass, 232.