and other railroads; 100 miles N. of Omaha. Here are Morningside College, Trinity College, a high school, college of medicine, a city normal school, St. Joseph, Samaritan, German Lutheran and St. Vincent hospitals, United States government building, public library, sanitariums, auditorium, waterworks, street railroad and electric light plants, several National and private banks, and numerous daily and weekly periodicals. The United States census for 1914 reported manufacturing establishments, employing $22,610,000 capital, and having a combined output valued at $49,452,000. The city contains large slaughtering and meat-packing plants, flour mills, gas engine works, candy factories, brick works, and the general shops of several railroads. Pop. (1910) 47,823; (1920) 71,227.
SIOUX FALLS, a city and county-seat of Minnehaha co., S. D.; on the Sioux river, and on the Illinois Central, the Great Northern, the Burlington, the Chicago, Milwaukee, and St. Paul and other railroads; 90 miles N. of Sioux City, Ia. It contains the Sioux Falls College (Bapt.), Lutheran Normal School, All Saints School, the State penitentiary, the State School for Deaf Mutes, libraries, several National and other banks, and several daily and weekly newspapers. The city is the seat of a Roman Catholic bishop, and of the Protestant Episcopal bishop of South Dakota. It has important jasper quarries, and manufactories of woolen and linen goods, boilers, brick, brooms, flour, soap, etc. The meat-packing industry is important. Pop. (1910) 14,094; (1920) 25,202.
SIOUX, or DACOTAH, INDIANS, a once powerful family of North American Indians. Their number is estimated at 25,000; they are well advanced in civilization and are increasing in population. In 1862, the Sioux under the lead of Little Crow, a noted chief, in consequence of the annuity not having been paid to their satisfaction, waged a most cruel and exterminating war on the whites of Minnesota; and so well concerted were their schemes that no less than 640 men, women, and children, and 94 soldiers, were killed before the massacre was stayed. As an atonement for their great crime in thus murdering the whites the Federal Government allowed only 38 out of 303 Indians found guilty by a proper tribunal, to be executed. This clemency, though seemingly unjust, was the result of mature deliberation on the part of the authorities at Washington, who found that the Indians had been greatly wronged, and in consequence of which they sought revenge. They are now divided into small branches, and located on several reservations, chiefly in North and South Dakota and Minnesota.
SIPHON, a curved tube having one branch longer than the other; used for transferring liquids from higher to lower levels. It acts by atmospheric pressure, and consequently cannot be depended on for overcoming heights greater than about 30 feet near the level of the sea, and a less height at greater elevations.
SIREN, in acoustics, an instrument for determining the number of vibrations corresponding to a note of any given pitch.
In classical mythology, certain melodious divinities who dwelt on the shores of Sicily, and so charmed passing mariners by the sweetness of their song that they forgot their homes and remained there till they perished of hunger. According to one legend, they threw themselves into the sea, from rage and despair, on hearing the more melodious song of Orpheus. Originally there were only two sirens; but their number was afterward increased to three, and their names are given with great variety.
SIRIUS, in astronomy, the dog star, by far the brightest fixed star in the sky. It is alpha Canis Major, situated a little below Orion, and is mythologically regarded as one of the hounds held in leash by Orion, Procyon in Canis Minor being the other. A line drawn from the Pleiades through the three stars of Orion's belt will pass it closely; straight lines connecting it with Procyon and Betelgeuse will constitute a nearly equilateral triangle; and Aldebaran, Betelgeuse, Sirius, and Regel, all of the first magnitude, form a lozenge-shaped figure, with Orion's belt in the center. Ptolemy, in the 2d century, ranked Sirius among red stars; now it is white, and is a very brilliant object, its light being 324 times as great as that of a star of the sixth magnitude. It is about 1,000,000 times as far from us as the sun, and its mass is about 20 times as great. Viewed by the spectroscope, its chief lines are those of incandescent hydrogen, with feebler ones of sodium and magnesium; the metal mercury seems also to be present. Some irregular movements of Sirius led to the belief that a heavenly body existed near enough to produce a perturbation, and a son of Alvan Clark, of Boston (Mass.), discovered, on Jan. 31, 1862, what appears to be a planet revolving around Sirius as its sun, it is thought in about 49 years. The heliacal rising of Sirius varies in different latitudes, and the procession of the equinoxes makes it do so also in successive ages. When the heliacal rising of Sirius (called by the old Egyptians Sothes) took
