theater is another fine building. There also are many beautiful monuments scattered through the city. The chief pleasure ground is the Grosser-Garten, in which are a summer theater and two museum. Near by, is the zoological garden. Dresden is famous for its artistic, literary and scientific collections. The most valuable of these is the picture-gallery, in the museum, which contains 2,500 pictures. This collection is one of the finest in Europe. The so-called Japanese palace contains a library of 300,000 volumes and collections of coins, ancient works of art, china and similar objects. Among the chief branches of industry in the town are manufactures in gold, silver, straw-plait and scientific and musical instruments. Dresden is known to have existed in 1206. It was almost entirely burned in 1491, but was soon rebuilt. In the first half of the 18th century Augustus I and II, Electors of Saxony, by their extensive improvements began to give the city the appearance it now has. The city suffered severely in the Seven Years' War, in the wars of Napoleon and in the Revolution of 1848. It has greatly improved in the last 25 years. Population, 546,882.
Dreyse (fon drī'ze), Johann Nicholas von, inventor of the needle-gun, was born in Prussia in 1787. He was a locksmith in his early^ years, but later worked in a gun-factory in Paris; after which he set up an ironware factory in his native town, where he spent most of his time in making improvements in firearms. In 1836 he completed the needle-gun, which was introduced into the Prussian army in 1840. The next year he opened a gun-factory, which soon supplied weapons for all the German states. He died in 1867.
Drift. Drift or glacial drift is the name given to the deposits made by the ice of the glacial period and by the waters which arose from the melting of the ice. The drift consists of bowlders, cobbles, pebbles, sand and clay, often mingled without trace of arrangement. The bowlders are often two or three feet in diameter, and occasionally 10 or 20 or even 30 feet or more. They are sometimes known as hard heads or, when black, as nigger-heads. They may be composed of any sort of rock over which the ice came. The stones of the drift are often striated. The clay of the drift is really rock-flour, being composed of the comminuted products of rock. The drift deposited by the ice direct)^ is often called till or bowlder-clay. It is not stratified. The drift deposited by the water to which the melting of the ice gave rise is stratified. It consists of gravel, sand or clay.
Drift covers most of the United States north of a line drawn along the south coast of New England, through Long Island, northern New Jersey and Pennsylvania, southern Ohio, Indiana and Illinois and thence along
the general course of the Missouri. Drift also covers most of British America, and there are local areas of drift in the western mountains south of the above line. There is a small area of 8,000 or 9,000 square miles, in southwestern Wisconsin and the adjacent corners of Illinois, Iowa and Minnesota, where drift is absent. This area is known as the driftless area.
The sources whence the materials of the drift came are often determinable. Thus, masses of native copper, which could only have come from the Lake Superior region, have been found in Illinois and Indiana. They show that the ice which made the drift of this region moved in a southerly direction. Bowlders from the Palisade ridge above New York are found on Staten Island and on the west end of Long Island, as well as in New York city, showing that the ice here moved to the southeast. The drift is in places as much as 500 feet thick, though its average thickness in the United States is probably not more than half the latter figure.
Drift also covers much of northern and northwestern Europe, reaching south to southern England, the mountains of Germany and to still lower latitudes in the western and central parts of Russia.
For full definition of the drift and its relations see Journal of Geology, Vol. II., pp. 708 and 837; and Vol. III., p. 70. For classification of the drift see the same journal, Vol. II., p. 517. See also Dana's Manual of Geology; Third Annual Report of the United States Geological Survey; and articles by Chamberlin, State Geological Reports, for the drift of the several states. R. D. Salisbury.
Dromedary. See Camel.
Drowning, accidental asphyxia, the remedy for which is the instant resort to artificial respiration and circulation, by supplying fresh air to the lungs and forcing the blood from the engorged right side of the heart. In cases of accidental drowning, where the victims have for some time been submerged, it is well to know what to do to recover them from the sea and how to proceed in the way of resuscitation. In reaching a drowning person, the first precaution on the part of the rescuer is to take care how to approach the victim in the water, after divesting oneself as speedily as possible of all impeding clothing. The general rules to be followed are as follows: In attempts to rescue, if the victim has sunk, the first thing to note is the spot where the body has gone down. If the water be smooth, this will generally be made plain by the air-bubbles which will occasionally rise to the surface, allowance being of course made for the motion of the water if in a tideway or stream, which will carry the bubbles out of the perpendicular course in rising to the surface. If the victim has not sunk but is still struggling on the surface, an assuring hail that help is near should be given; though in ap-
