Artesian Wells
deep wells bored through impervious rock strata to a porous water bearing rock stratum whence the water flows to the surface and is discharged from the bore. The principal condition of an artesian well is a pervious stratum protected above and below by a water-tight bed. These layers come to the surface in some elevated region where they get their rain flow, then pitch downward to a considerable depth and then rise again, thus forming a great basin which retains the water. Rain water and surface brim. If it be tapped any, the water will rise in the bore and be discharged as long as the supply equals the demand. The whole Mississippi valley is ideally adapted for wells of this kind.
The Chinese and Egyptians were early acquainted with artesian wells. The oldest known in Europe is at Lillers, in was sunk in 1126. In 1836, the first Sahara and at a depth of nearly 200 feet struck water which poured forth 4,500 liters a minute. In 1860 there Sahara and at a depth of nearly 200 feet struck water which poured forth minute. In the province of Constantine alone there are more than 150. The re- 4,500 liters a minute. In 1860 there the country materially, but also to the character and habits of its nomadic Arab inhabitants. Several tribes have already settled down around these wells, and, forming thus the centers of settlements, have constructed villages, planted date palms, and entirely renounced their previous wandering existence. The earliest exploration for artesian water and, forming thus the centers of settle- ments, have constructed villages, planted date palms, and entirely renounced on the Kansas Pacific railroad. It was sunk to a depth of 1,300 feet without obtaining water. In 1879, a well was drilled for petroleum at South Pueblo, in the Arkansas val valley. At a depth of 1,180 feet a flow of mineral water (82°) was struck yielding 160,000 gallons per 24 hours. Subsequently thousands of wells were dug in Colorado. It was in the Arkansas valley. At a depth of 1,180 feet a flow of mineral water (82°) body of artesian water. The American Desert, which includes one-fifth of the total area of the United States, has deep artesian wells which were bored have transformed the whole region. The most famous artesian well, perbrought from the Gault haps, is that of Grenelle, near Paris, gallons of water per minute. tion of the data upon which the internal Artesian wells have supplied a porgallons of water per minute. whose water is bro at a depth of 1,798 feet. It yields 5162 for the purpose of irrigation, and which have transformed the whole region. only 53°. Mм.
Artesian wells have supplied a portion of the data upon which the internal temperature of the earth has been calculated. Thus the Grenelle well has a temperature of 81° F., while the mean temperature of the air in the cellar of the Paris observatory is onl found that there was a gradual and regular increase downward. Walferdin also made a series of very accurate and careful observations on the temperature down to a depth, the one of 2,678 feet, of each other, commencing at a height of 1,030 feet above the sea, and going down to a depth, the one of 2,678 feet, the other about 1,900 feet. The results, after every possible precaution had been taken to insure correctness, gave a rise of 1° F. for every 55 feet down to a depth of 1,800 feet, beyond which the rise was more rapid, being 1° for every 44 feet of descent; but at Fort Randall the temperature at 80° increased at the was purer than from ordinary wells; but it is found to be a mistake. The rate of 1º every 17½ feet. It was once supposed that water from artesian wells but it is found to be a mistake. The lower the water goes, the more impregnated it is with saline and other matter. velt, ar'te-vel-de), the name of two men ARTEVELD, or ARTEVELDE (ar'tedistinguished in the history of the Low distinguished in the history of the Low Countries. (1) JACOB VAN, a brewer of Ghent, born about 1300; was selected their struggles against Count Louis of Flanders. In 1338 he was appointed captain of the forces of Ghent, and for several years exercised a sort of sovereign power. A proposal to make the an insurrection, in which Arteveld lost Black Prince, son of Edward III., of England, governor of Flanders led to his life (1345). (2) PHILIP, son of the former, at the head of the forces of Ghent, gained a great victory over the Count of Flanders, Louis II., and for a time assumed the state of a sovereign prince. His reign proved short-lived.
The Count of Flanders returned with rash enough to meet them in the open The Count of Flanders returned with a large French force. Arteveld was rash enough to meet them in the open and Ghent, in 1382, and fell with 25,000 Flemings.
ARTHRITIS.