SUN. 698 SUNBURY. collection of several spots. They are by no means immovable upon the solar surface, but have a motion of their own, those near the sun's equa- tor traveling farther from the poles, and those in higlier solar latitudes increasing their dis- tance from the equator. But no sun-spots are ever foimd farther from the solar equator than latitude 45°, and few are nearer the equator than latitude 5°. One of the most remarkable things about the spots is the fact that their frequency is periodic. Once in about eleven years they have a maximum frequency, and as- tronomers are able to record their occurrence in greater numbers than usual. The cause of this periodicity is unknown. Verj' interesting questions are raised by a study of the sun's light and heat. The quan- tity of light given by the sun, as compared with a standard candle, can be measured, and the sun's 'candle power' thus made known. Experi- ments show that this candle power is repre- sented by the number 1575 with twenty-four zeros attached. The quantity of solar heat is no less stupendous; it has been estimated that the heat given out each hour by the sun is equiva- lent to the burning of a quantity of coal sufficient to cover the entire solar surface to a depth of more than twenty feet. The source of this vast amount of light and heat has been for a long time a mystery. It cannot be a question of com- bustion, because in that case the sun would have been consumed long ago, even if made of solid coal. The theory at present accepted is due to Helm- holtz. It assumes that the sun's bulk is slowly contracting, and that the energy thus produced is turned into heat. It has been computed that a diminution of 150 feet annuallj' in the sun's radius would be sufficient to account for the heat developed. Such a contraction would remain invisible even in our most powerful telescopes until it had continued for at least 10,000 years, and the process would need to continue for ten million years before the sun would lose the power to give us heat enough to keep life on the earth. The rotation of the sun on its axis occupies about 25 days. 8 hours. This period is deter- mined by watching the spots go around with the sun ; and it is somewhat luicertain, because, as we have seen, the spots are not themselves quies- cent on the solar surface. The rotation axis is inclined to the ecliptic plane, like that of the earth ; if continued to the celestial sphere, it would pierce it midway between the bright star Lyra? and the Pole star. And there is one very peculiar feature in the rotation due perhaps to the fact that the sun's vast bulk has not yet been completely transformed from the gaseous to the liquid or solid stage. The equatorial regions rotate faster than those in higher latitudes, showing the existence of strong rotary surface currents of different velocities. No thoroughly satisfactory explanation of this phenomenon has yet been obtained by astronomers. See Eclipse; Plakets ; Perturbations ; Orbit ; Solar Sys- tem. Consult: AsirophysicalJoumal (Chicago); Kaver, Eandhuch der Spectroscopic (Leipzig, 1902) ; Young, The Sun (New York, 1900); Loekj-er, Solar Physics (London, 1874) ; Proctor, Sun (London, 1871). SUN, Temple of the. An immense temple of ancient Rome erected by Aurelian, after the tak- ing of Palmyra, on the site of the early Pulvinar Soils on the Quirinal Hill. It was built in imita- tion of the Eastern sanctuaries of the sun, and ' stood on a platform 92 feet high, from which the tenyjle rose to a height of 110 feet. It was approached by two staircases, the steps of which now form the approach to the Church of the Aracujli, to which they were removed in 1348. Tlie temple was of massive proportions. The 44 pillars of its peristyle were US feet high and 7% feet in diameter, and a single fragment of the • cornice, now in the Colonna gardens, weighs 100 tons. The vaults in the substructure were utilized for the storage of wines. The last portion of the temple, which formed part of the fortifications of the Colonnas, was destroyed about 1595, and the only remains of the build- ing are three blocks in the Villa Colonna. The material was used in the Pope's palace on the Quirinal, Santa Maria Maggiore, and other buildings. SUN AND LION, Order of the. A Persian civil and military order of merit with five classes, founded in 1808 by Shah Feth Ali on the model of the French Legion of Honor. The decoration is a silver star, bearing a lion with a sword. See Plate of Orders. SUN ANIMALCULE. See Heliozoa. SUNBIRD. A bird of the tropical passerine family Nectarinidae, which may be regarded as occupying nearly the same place in the Old World as do the humming-birds in America. They are all of small size, although none are so small as the smallest humming-l)irds, which they rival in brilliancy of plumage. Like them, they feed partly on the nectar of flowers, which they suck by their long bill, but chiefly on the minute insects which the flowers attract; they do not, however, flutter on the wing when feeding, like huuuning-birds. but perch on or beside the flower into which the bill is to be in-' serted. The species are very numerous, and are natives of the southern parts of Asia, the East- ern Archipelago, and Africa. The resplendent metallic phnnage belongs only to the male, and only to the breeding season. They have been described and depicted in a magnificently illus- trated monograph by Shelley. The 'Sectarinidee (London, 1876-80). "See Plate of Creepers. SUN-BITTEBN (so called because of its bril- liant ocellated plumage). A curious bird of South and Central America, about the size of a chicken, allied to the cranes and more closely to the kagu (q.v.), the two species of which con- stitute the genus Eurypyga and the family Eury- pygidK. It havmts river banks, feeds upon small fish, crustaceans, and insects, and utters a soft or plaintive, long-drawn whistle. In the mating season it executes a fantastic dance, with its wings spread about its head, showing a pattern conqiarable to the sun's rays. Its nest is a rude allair in a biish or on a low tree branch. The best-known species is Eurt/pi/fia hclias. which is beautifully variegated with brown, black, and white tints. This bird is often domesticated by the Brazilians. Consult Newton, Dictionar;/ of Birds (New York, 1896). See Plate of Bustards. SUN'BURY. The county-seat of Nortluim- berlaiul County, Pa., 54 miles north of Harris- burg, on the Susquehanna River, and on the Penn- sylvania and the Philadelphia and Reading rail- roads (Map: Pennsylvania, E 3). There arc the
