Part 21

Apples, 171.

Arab Traditions, 194. (See Moslem.)

Arago, quoted, 41, 42.

Archimedes, 94.

Archimedes Crater, 151–153, 155.

Arctic Cold, 159.

Arctic Pole, 96.

Arcturus, 208, 211.

Aristillus Crater, 151.

Aristotelian Philosophy, 8.

Arzachel, 156, 161.

Asteroids, 128.

Astrology, 127.

Astronomers and Priests, 1–3. (See American, New, Old.)

Astronomical Day, 85, 86.

Atmosphere, 136, 180; as a shield, 216, 220. (See Air.)

Atolls, 152.

Auger, simile, 31.

Aurora Borealis, 35, 67, 212.

Autolycus Crater, 151.

Axis, 9, 10.

Babel, 96.

Bain Telegraph, 88.

Balloons, 176.

Bees, 124. (See Insects.)

Berkeley’s Theory, 70.

Berlin Observatory, 233.

Bernières’s Lens, 103.