Respiration by means of exporting a copy, or a pot filled with water, 15. Stephenson, George, 63, 375. Stop, in lens, 244; iris, 249; use of, 249. Spectrum, colours of, 230. Speed governors, 67, _68_, _69_; Hartwell, 70; marine, 71. Speed of motor car, 105. Coal, as fuel, 15; gas, 394; gas plant, _396_; gas, purification of, 397. Cochlea, 273. Coherer, 140. Coil, Ruhmkorff, 121. Coke, 395. Combinations in Chubb lock, 436; Yale lock, _436_, _437_. Yellow spot, in eye, 251. Spring balance for watches, 425. Rods of Corti, 274. Ruhmkorff coil, 121, _122_. Safety-valve.