SOUND 497 SOUTH AFRICA residence at Dusseldorf, but was per- mitted to return to France in 1819; and in 1827 was raised to the peerage. After the July revolution of 1830, and on two subsequent occasions, he held ministerial office, and in 1846, on retiring from pub- lic life, was created Grand-Marshal of France. He died in St. Amans, Nov. 26, 1851. SOUND, strictly the sensation which results from the stimulating action of at- mospheric or other vibrations upon the aural nerves. Beyond ourselves it has no existence, it is purely subjective, and as a sensation must be carefully distin- guished from the vibratory motion which is one of the necessary conditions of its existence. Further, the existence of this vibratory motion is itself conditioned by two things — a distributing cause and a suitable medium for transmitting the dis- turbance to the ear. The study of these in all their possible relations constitutes the science or theory of sound. Sounds are usually classified under the two heads of noises and musical sounds. A musical sound is caused by a regular series of exactly similar disturbances or pulses succeeding each other at precisely equal intervals of time; if these conditions are not fulfilled, the sound is a noise. SOUNDING, the operation of trying the depth of water and the quality of the bottom, especially by means of a plummet sunk from a ship. In navigation two plummets are used, one called the hand lead, weighing about eight or nine pounds ; and the other, the deep sea lead, weighing from 25 to 30 pounds. The former is used in shallow waters, and the latter at a distance from shore. The nature of the bottom is commonly ascertained by using a piece of tallow stuck upon the base of the deep-sea lead, and thus bring- ing up sand, shells, ooze, etc., which adhere to it. The Thomson sounding apparatus con- sists of an iron drum attached to a frame. The wire to which the lead is attached is wound around a grooved disk controlled by a clutch. A dial on one side of the frame registers the depths. The Sigsbee sounding device is the invention of Ad- miral Sigsbee, U. S. N. SOURABAYA, or SURABAYA, a sea- port of Java, capital of a province of the same name (area, 2,091 square miles; pop., about 3,000,000), on the Strait of Madura. It possesses a large and secure harbor; a building yard, graving dock, and an extensive trade in exports of na- tive produce, and imports of European manufactures. Pop. about 175,000. SOURAKARTA, or SOLO, a town of Java, capital of the province of the same name (area, 2,404 square miles; pop. about 1,750,000), 140 miles W. S. W. of Sourabaya. It has manufactures of cot- ton and other tissues, leather, etc. Pop. about 125,000. SOUSA, JOHN PHILIP, an American musician and conductor, born in Washing- ton, D. C, in 1854. He studied music and began teaching at the age of 15. From 1880 to 1892 he was the leader of the United States Marine Corps band. In the latter year he organized his own band, and for many years successfully toured Eu- rope and the United States. In 1911 he JOHN PHILIP SOUSA made a tour of the world. He was a pro- lific composer of music, especially of marches, many of which attained wide success. He also wrote music for several operas. He wrote "The Fifth String" (1905); "The Dwellers in the Western World," and "Through the Year with Sousa" (1910). During the World War he conducted musical instruction at the Naval Training Station, Great Lakes, and there organized a remarkable band which was used in recruiting in various parts of the country. SOUTH AFRICA, UNION OF, a polit- ical division of South Africa, extending from the southernmost point of the Afri- can Continent to the course of the Lim- popo river, i.e., from 34° 50'-22° S. lati- tude, and including all the British terri- tories within those limits, with the excep- tion of Basutoland and the Swaziland and Bechuanaland Protectorates, while provi-
