In 1848 the last operation was commenced under the direction of Maj. Welton. The strata first penetrated were alluvial sands, saturated with water, which caused them to run as quicksand. These were shut out by cast-iron tubing of 6 in. diameter, which penetrated the clays and marls of the postpliocene formation, and finally reached the depth of 230 ft., where it rested upon a rock of the eocene formation. From this point down alternations of hard rock and loose sands were met with, the latter causing the same trouble as those above, running in and filling the well, sometimes even to the height of 140 ft. up from the bottom in a single night. When it was found impossible to draw out the sands from these beds, the plan was adopted of shutting them out by tubing. The bore of the lower part, being first enlarged from 3 1/2 to 5 1/2 in., was lined with sheet-iron tubes to the depth of 700 ft. Sand flowing in at 1,020 ft. rendered it necessary to ' take out the tin tubing, and replace it with heavier tubes of 4 in. diameter and 7/8 in. thick, which screwed one upon another; this was done to the depth of 1,102 ft. The sinking was extended, of 3-inch bore, to 1,250 ft., the last strata being sandstones, sand, and marls, probably of the cretaceous formation.

The discharge, 10 ft. above the surface, is about 1,200 gallons an hour. The water is saline, and disagreeable to the taste, but soft. Its temperature is 87°. - In Onarga, Iroquois county, 111., 85 m. S. of Chicago, there are artesian wells that deserve especial notice, both because of their number (over 200 within a radius of 20 m.), and from the fact that they are all flowing wells, though the average depth does not exceed 70 ft. They are sunk with an auger 6 in. in diameter, and the water vein, a bed of white sand, is reached after boring through 5 ft. of surface soil. 10 to 20 ft. of common sand, 15 to 20 ft, of blue clay, and 20 to 30 ft. of hardpan, a mixture of clay and gravel. The flow, which rises several feet above the surface, varies in amount from 20 to 120 gallons per minute. It has been estimated that the daily yield from these wells is 53,400,000 gallons. It is a fact worthy of note that the district in which they are located is at a level of 92 ft, above that of Lake Michigan, and that the nearest probable fountain head is at least 200 m. distant. This dependence upon a distant source of supply is also demonstrated by the famous Chicago wells. One of these has a surface diameter of 5 in., which is reduced to 4 1/2 on nearing the bottom, at a depth of 711 ft.

The other is 5 in. in diameter from top to bottom; the first 42 ft. are lined with an iron tube, which projects 22 ft. above the surface; from this level the water flows at the rate of 432,000 gallons per day, and with a resisting power of from 600 to 800 lbs. The site of both wells is 82 ft. above the level of the lake, and the general character of the surrounding country is flat; whence it is conjee-tared that they may be fed from the region of the Rock river, 100 m. distant. - Though the geological structure of Manhattan island is exceedingly unfavorable, yet several artesian wells were sunk in the city of New York years ago by Mr. Levi Disbrow. One of the oldest and deepest of these wells is at the United States hotel, known when the well was sunk as Holt's, on Pearl, Fulton, and Water streets. The boring for the first 126 ft. was in stratified sands and blue clay alternating with river mud. At this depth the surface of the rock was struck under a bed of coarse gravel; and below this the shaft was continued in the gneiss rock 500 ft. further. The upper 200 ft. of the well was bored 3 in. in diameter; the remainder was 2 1/2 in. The water for a time was tolerably good, but soon became impregnated with the salt river water, and at last unfit for use.

At the corner of Bleecker street and Broadway a well was sunk 448 ft., of 7 in. bore - the first 42 ft. through sands and gravel, and 406 ft. through the hard gneiss rock of the island. The water, as stated by Mr. Disbrow, rose within 30 ft. of the surface, to the amount of 120,000 gallons in 24 hours. At the dry dock, 11th street, East river, the rock, met with at 130 ft., was penetrated 200 ft. further. Many other wells of this nature have been sunk in and near the city, but with no features of particular interest. - In considering the methods of boring artesian wells, and examining the implements now used, it is interesting to note the similarity between these and those employed by inhabitants of China centuries ago. The missionary Imbert stated in 1827 that in the province of Ou-Tong-Kiao, in a district 10 leagues long and 4 wide, these wells may be counted by "tens of thousands," sunk at very remote periods for the salt water and bituminous matters which they emit. These products are met with at the depth of nearly 1,800 ft,, and some of the wells that had lost them have been carried down even to 3,000 ft. . From this enormous depth currents of carburetted hydrogen come up in such quantity that it is used to furnish heat for evaporating the salt water. (The gas from the Pennsylva-nia oil wells is often burned under the steam boilers.) Instead of using rods to sink their wells, the Chinese suspend the cutting drill, which is attached to a heavy metal rod 6 ft. long and 4 in. in diameter, by a rope or chain, which passes over a wheel.

Around the drill is a cylindrical chamber, which by means of sim-ple valves takes up and holds the broken fragments. As the rope is raised and dropped, it gives by its torsion a turn to the drill, causing it to vary its position at each stroke. When the cylinder requires to be discharged, it is easily wound out by a windlass or horse-whim. The rope is protected from wear by knobs of wood attached to it at intervals. This principle has been successfully applied in Germany to sinking holes for ventilating mines; with large drills 18 in. in diameter a hole of this size has been carried down several hundred feet, - The demand for improved methods of sinking these wells which the opening of the Pennsylvania oil region created, has resulted in the introduction of many ingenious labor-saving appliances, though the attention of the oil men has been chiefly directed toward the devising of methods by which the boring tools may be safely and quickly removed in case of accident. A general description of the processes of boring, tubing, and pumping, as practised in western Pennsylvania, may best serve to illustrate the latest advances made in the methods of sinking artesian wells.