Page:The American Cyclopædia (1879) Volume I.djvu/815

 ARTESIAN WELLS 779 of which is connected with the working beam by jointed poles or metal rods. When it is desirable to exclude all water from above a given point, it is effected by binding around the tubing a leather bag of flax seed before Boring Tools in Operation Pennsylvania Oil Region. driving it down; the swelling of this closes the space between the main wall and the tube. The steam engines in use in western Pennsyl- vania range from 6 to 20 horse power, one of 8 horse power being sufficient to bore a well 900 ft. deep. Artesian wells have been sunk, though very slowly, by the aid of two men and an old-fashioned spring pole. Among the accidents liable to occur in the bor- ing of artesian wells, are the breaking of the drills, or their detachment from the auger stem, and the loss of the sand pump or the whole boring gear by the wearing away of the drill rope. At times the drill enters what is known as a mud vein, a thin stratum of mud or quicksand, which often flows in so rapidly as to enclose and bury the drilling tools. There are many ingenious contrivances for the removal of these obstruc- tions, and the forms of several of the less com- plex are shown in the cut. Fig. 1 is designed chiefly for removing detached or broken pipe Simplest Boring Apparatus. Tools for ^^s Obstruc- tions. or rods. It is lowered down the well bore until the rod passes up above the ends of the two arms, when by an upward movement the two catches, being pressed forward by springs, take hold of the rod and grasp it the more firmly the greater the resistance. Fig. 2 is of service mainly in removing a detached drill or reamer; the shorter arm acts as a guide, while the hook at the end of the larger one passes below and takes hold of the low- er edge of the drill. Figs. 3 and 5 are also designed for removing broken rods. In 3 the rod passes through the metal cylinder, and is prevented from fall- ing back by the drop- 5 v -j J. T-,. r catch and spring. Fig. 5 consists of an angular claw placed at right angles to the rod by which it is lowered ; this is twisted under the shoulder of the rod, thus securing it as in a wrench. Fig. 4 is the ordinary lazy tongs, and is of very gen- eral service, as its construction indicates. In addition to the contrivances above men- tioned, the French engineers have introduced certain improved drills, pumps, &c. The drill invented by M. Goulet-Collet consists of a cylinder of sheet iron 6 ft. long, suspended by a chain, and armed at its lower end with an annular cutting head of steel, in which two knives or chisels are inserted at right angles across the opening. These chisels serve to cut the rock, which when finely divided rises with the water through the openings; these may be provided with valves, the instrument thus serving the double purpose of drill and pump. The method of boring by means of the diamond drill is essentially different from that described above. (See BOEING.) When a well fails to yield a fair amount of oil or water, an increase in the flow is often effected by means of the Roberts torpedo. This is a thin water-tight cylinder of metal or paper, 4 to 6 ft. long and 2 or 3 in. in diameter, charged with powder, guncotton, or nitro- glycerine. It is lowered to the bottom of the well, or to a depth that will bring it opposite the desired stratum, and the well then flooded. The charge is exploded by a cap or electric spark, and the explosion often clears away the obstruction from the oil or water vein. Wells yielding only 5 bbls. of oil per day have been increased by this means to 75 or 100 bbls.- Negative artesian wells are those which serve to convey away surface waters into some ab- sorbing stratum. They are of service about manufactories from which large quantities of