Dull lurid red, and the health of the oscillating periods.
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; signalling, 228; stoker, 399. Backfall, 298. Balance-wheel, 419. Ball cock, 366, _367_. Balloon.