SACRAMENTO                                           1652                                       SAFETY-VALVE

Pacific Railroad, covering 25 acres. Sacramento was settled in 1839 by a Swiss, who built a fort in 1841. It was not till 1848, after the discovery of gold, that the city, at first a town of tents, was laid out. It became the capital in 1854. Population 44,690.

Sacramento, the largest river of California, rises in the northeastern part of the state, and flows southwest through the Sierra Nevada to Shasta, south to Sacramento and thence southwest into Suisun Bay, through which its waters pass into San Pablo Bay and to the Pacific. It is about 500 miles long, and is navigable for small boats to Red Bluff, nearly 250 miles. Its chief branch is the San Joaquin.

Sacs and Foxes, Indian tribes which settled near Green Bay, Wis. They lived and usually acted together. Both belong to the Algonquin family. Among the Sacs the children of each family at birth are marked white or black in turn, thus dividing the tribe into two bands, the white or Kis-coquah and the black or Oshkosh. The Foxes also were in two branches, the Out-agamies (foxes) and the Musquakink (men of red clay). Both tribes were daring and warlike, fighting courageously the much more numerous Iroquois and Sioux. The French had no greater enemies and the English no greater friends than the Foxes, who attacked Detroit in 1812, and were cut to pieces at Presque Isle on Lake St. Clair, to which they had retreated. The Sacs on the whole favored the English, serving under Pontiac, supporting the British in the Revolutionary War and fighting under their renowned chief, Blackhawk, in 1832 to recover their hunting grounds from the. United States. In 1857 a party of 317 Sacs and Foxes bought lands at Tama, la., which they have worked, becoming industrious and self-supporting. The two tribes now number about 1,000, separate bands living in Iowa, Nebraska, Kansas and Oklahoma.

Sadi [sa'de), the assumed name of Sheikh Muslih Ad-din, one of the most celebrated of Persian poets, who was born at Shiraz about 1184. Little is known of his life. His father's name was Abdallah, and he was a descendant of Ali, Mohammed's son-in-law. He studied science and theology at Bagdad. He traveled for many years in parts of Asia, Africa and Europe The catalogue of his works contains 22 different kinds of writing in prose and poetry, in Arabic and Persian. The greater part are odes and dirges. The finest of his works is Gulistan or The Flower-Garden — a kind of moral work in prose and verse, made up of eight chapters on such subjects as kings, old age and education, with stories, puns and maxims. Two others of his works are Bustan or The Tree-garden and Pand-Namah or The Book of Instructions. See

Robinson's Persian Poetry for English Readers and Sir Edwin Arnold's With Sadi in the Garden.

Sadowa (sä-dő'vĺ), a Bohemian village 58 miles northeast of Prague, where an important victory was gained by 240,000 Prussians under King William I over 220,-ooo Austrians under General Benedik, July 3, 1866. The battle lasted from 8 A. M to 4 P. M., and resulted in the rout of the Austrians, who lost 21,000 men and 22,000 prisoners. The Prussian loss was 9,000 men. This battle, which is often called Königgratz from a town eight miles distant, decided the Austro-German or Seven Weeks' War of 18Ŏ6.

Safe'ty=Lamp. When marsh-gas, which is often set free in large quantities from coal-seams, is mixed with ten times its volume of air, it becomes highly explosive. Moreover, this gas, the fire-damp of mines, in exploding, renders ten times its bulk of air unfit for breathing, and the choke-damp thus produced is often as fatal to miners as the first explosion. To do away with these dangers, Sir Humphry Davy began his experiments on flame, which resulted in his invention of the safety-lamp. He found that when two vessels filled with a gaseous explosive mixture are joined by a narrow tube and the contents of one fired, the flame does not reach the other, provided the thickness of the tube, its length and the conducting power for heat of its material bear certain proportions to each other; the flame being put out by cooling and its transmission made impossible. He found also that high conducting power and less thickness make up for less length; and to such an extent may this shortening of length be carried that metallic gauze, which may be looked upon as a series of very short, square tubes arranged side by side, wholly stops the passage of flame in explosive mixtures. His lamp consists of a burner inclosed in a wire-gauze. When such a lighted lamp is brought into an explosive mixture of air and fire-damp, the flame is seen slowly to enlarge as the amount of fire-damp increases, until it fills the entire gauze-cylinder. Whenever this pale, enlarged flame is seen, the miners should at once get to a place of safety; for although no explosion can take place while the gauze is sound, yet at that high temperature the metal becomes rapidly burnt and might easily break, and a single opening, if large enough, would then cause a destructive explosion. Many improvements have since been made in Davy's lamp.

Safe'ty-Valve, an appliance for obviating or diminishing the risk of explosion or collapse in steam-boilers, by allowing steam to escape or air to enter. The forms of safety-valves are various but the principle of all is the same, — that of opposing the pressure within the boiler by such a force