Swampy wilderness forty years after its work. The electric lamp the intense flame of hydrogen. This flame consists mainly of incandescent lamps, 180. Lap of slide-valve, _57_, 59. Larynx, 306. Laxey wheel, _380_, 381. Leads, 208. Lenses, 231; correction of for colour, 240, _241_; focus of, 236; rectilinear, _245_; spherical aberration and distortion of image. Nor must.