Climatology, 317-329; climate, general sense of, 317, 318.
Clouds, their electric tension, color, and height, 236, 337; connection of cirrous strata with the Aurora Borealis, 196; cirro-cumulus cloud, phenomena of, 197; luminous, 202; Dove on their formation and appearance, 315, 316; often present on a bright summer sky the "projected image" of the soil below, 316; volcanic, 233.
Coal formations, ancient vegetable remains in, 280, 281.
Coal mines, depth of, 158-160.
Colebrooke on the snow-line of the two sides of the Himalayas, 31.
Colladon, electro-magnetic apparatus, 335.
Columbus, his remark that "the Earth is small and narrow," 164; found the compass showed no variation in the Azores, 181, 182; of lava streams, 245; noticed conifers and palms growing together in Cuba, 282; remarks in his journal on the equatorial currents, 307; of the Sargasso Sea, 308; his dream, 310, 311.
Comets, general description of, 99-112; Biela's 43, 86, 107, 108; Blaupain's 108; Clausen's 108; Encke's, 43, 64, 86, 107-108; Faye's 107, 108; Halley's, 43, 100, 102-109; Lexell's and Burchardt's 108, 110; Messier's 108; Olbera's, 109; Pons's 109; famous one of 1608, seen in Persia, called "nyzek," or "petit lance," 189; comet of 1843, 101; their nucleus and tail, 87, 100; small mass, 100; diversity of form, 100-103; light, 104-106; velocity, 109; comets of short period, 107-109; long period, 109-110; number, 99; Chinese observations on, 99-101; value of a knowledge of their orbits, 43; possibility of collision of Blela's and Encke's comets, 107, 108; hypothesis of a resisting medium conjectured from the diminishing period of the revolution of Encke's comet, 106; apprehensions of their collision with the Earth, 108, 110, 111; their popular supposed influence on the vintage, 111.
Compass, early use of by the Chinese, 180; permanency in the West Indies, 181.
Condamine, La, inscription on a marble tablet at the Jesuit's College, Quito on the use of the pendulum as a measure of seconds, 166, 167.