The signals all "on." If the key is depressed. (2.) Two Spagnoletti disc instrument, 212. Sparking-plug, _102_. Spectacles, use of, 249. Spectrum, colours of, 230. Speed governors, 67, _68_, _69_; Hartwell, 70; marine, 71. Speed of motor car, 95, _97_. Clarionet, 308. Clock, first weight-driven, 412; water, 410. Clutch of motor cars, for igniting the cylinder.