Note.—Figures in italics signify that an illustration of the thing referred to appears on the page.
Aberration, spherical, of lens, 243. Acoustics, 294. Achromatic lens, 243. Action carriage of piano, 283. Advancing the spark, 102. Air-gun, 342 . Air-pump for cycle tyres, 340 ; for Westinghouse brake, 199. Alternating currents, 164; dynamo, 164. Amperage, 125. Angle of advance, 57, 58; incidence, 268; reflection, 268. Aorta, 360. Arc lamp, 182. Archimedes, 412. Armature, 162. Arteries, 358. Arterial blood, 359. Atmospheric pressure, 350. Auditory nerve, 272. Automatic brakes, 188;