TROPIC 12 TROSSACHS TROPIC, in astronomy, one of the two small circles of the celestial sphere, sit- uated on each side of the equator, at a distance of 23° 28', and parallel to it, which the sun just reaches at its greatest declination N. or S., and from which it turns again toward the equator, the N. circle being called the Tropic of Cancer, and S. the Tropic of Capricorn, from the names of the two signs at which they touch the ecliptic. The stars are brighter in the tropics than in the temperate zones, and astro- nomical observation is easier. Cyclones arise within the tropics. The charac- teristic vegetation of the tropics con- sists of gigantic endogens, as palms, some of which rise to a height of from 100 to 200 feet. More polypetalous exogens are arborescent than in tem- perate climes. The Coniferse exists chiefly on mountains. Ferns abound in tropical islands, and deltas where water is plentiful, so that in some localities from 250 to 300 species may be gathered. The tropical type of vegetation was sep- arated at a remote period into two por- tions, one in the Old World, the other in the New. Shells are brighter than in lands where the sun is less powerful, the birds more numerous and of gayer plumage, the feline tribe larger and in greater numbers. In geography, one of the two parallels of terrestrial latitude corresponding to the celestial tropics, being at the same distance from the terrestrial equator aa the celestial tropics are from the celes- tial equator. The one N. of the equator is called the Tropic of Cancer and that S. of the equator the Tropic of Capri- corn. Over these circles the sun is ver- tical when his declination is greatest, and they include that portion of the globe called the torrid zone, a zone about 47' wide, having the equator for a central line. The regions lying between the Tropic of Cancer and the Tropic of Capricorn, or near them on either side, are called the tropics. TROPIC BIRD, a popular name for any species of the genus Pfmethon. They are tropical sea birds, in habits and gen- eral appearance approaching gulls and terns, and resembling the latter in their mode of flight. Their powers of flight are great, and they are usually seen at considerable distances from the land, as they live almost entirely on the wing, and when they do not return to the distant shore to roost, rest on the surface of the water. They are about 30 inches long, of which the long tail feathers oc- cupy about one-half. The general hue of the plumage is white; in two species, Cyc from the Atlantic Ocean, P. setherins (or candMus) and P. flavirosMs, the . tail feathers are white; in the third spe- cies, P. phcenicurus, from the Pacific Ocean, they are red, and are highly > valued by the natives of the South Seas fis ornaments. Tropic birds nest in holes TROPIC BIRD in cliffs and on rocky islands, the female laying only one Qgg, and the male sitting in a hole by her side, both with heads inward. TROPINE, CsHisNO; an organic base obtained by heating atropine with a saturated solution of baryta water, and precipitating the baryta with carbonic acid gas. It has a strong alkaline reac- tion, is soluble in water, alcohol, and ether, melts at 62°, and boils at 229°. From its ethereal solution it crystallizes in colorless anhydrous tables. TROPPAXr, the chief town and capi- tal of the former Austrian Silesia; on the Oppa; 106 miles S. S. E. of Breslau. It is surrounded by fine gardens, replac- ing the old walls and intrenchments, and has three suburbs, six churches (one Evangelical), an old town hall (lately rebuilt in Gothic style), a large barrack, a higher gymnasium and realschule, a teachers' training college, a commercial school, and several benevolent institu- tions. Troppau manufactured, before the World War, cloth (chiefly military), ma- chinery, beet sugar, beer, potash, soda- water, lucifers, spirits, liquors, and paper. Troppau was founded in the 13th century. From Oct. 20 to Dec. 20, 1820, a congress of representatives of the five great powers, afterward transferred to Laibach, met here to plan for suppress- ing revolutionary outbreaks in Italy. Pop. about 35,000. TROPPO, in music, an Italian term for too much. TROSSACHS. a romantic defile form- ing an approach to the W. Highlands of 1 *^ Vol. X
