the autumn, some progress will have been made in that locality toward the establishment of a similar school. Other districts will doubtless follow, and the result will be, to quote the words of Sir W. Siemens on a late occasion, that "by the dissemination of science a higher spirit will take possession of our artisans; that they will work with the object of obtaining higher results, instead of only discussing questions of wages." It is on the mutual co-operation in this spirit of all the workers of every grade in our great craft that we may build the hope—nay, that we may even cherish the certain expectation—of placing it on even a higher eminence than that which it has already attained.

THE "SWALLOW," A NEW VEHICLE.

The graceful vehicle shown in the accompanying cut is much used in Poland and Russia, and we believe that it has already made its appearance at Paris. The builder is Mr. Henri Barycki, of Warsaw, who has very skillfully utilized a few very curious mechanical principles in it.

THE SWALLOW.

The driver's seat is fixed in the interior of a wide ring to which are fastened the shafts. This ring revolves, by the aid of three pulleys or small wheels, within the large ring resting on the ground. It will be seen that when the horse is drawing the vehicle, the friction of this large wheel against the ground being greater than that of the concentric one within it, the latter will revolve until the center of gravity of the whole is situated anew in a line vertical to the point at which it bears on the ground. The result of such an arrangement is that the driver rolls on the large wheel just as he would do on the surface of an endless rail. As may be conceived, the tractive stress is, as a consequence, considerably diminished.

There are two side wheels which are connected by a flexible axle to the seat of the carriage, but these have no other purpose than that of preventing the affair from turning to one side or the other.

The "swallow," for so it is named, is made entirely of steel and wrought iron. It is very easily kept clean; the horse can be harnessed to it in three minutes; and, aside from its uses for pleasure, it is capable of being utilized in numerous ways.—La Nature.

[Our excellent contemporary, La Nature, is mistaken in its account of the above vehicle. It is an American invention and was first published, with engraving, in the SCIENTIFIC AMERICAN, December 16, 1882.]

BORING AN OIL WELL.

HOW THE HOLE WAS MADE AND THE OIL BROUGHT UP.

A letter from Bradford, Pa., says: The machinery used in boring one of these deep oil wells, while simple enough in itself, requires nice adjustment and skill in operating. First comes the derrick, sixty feet high, crowned by a massive pulley.

The derrick is a most essential part of the mechanism, and its shape and height are needed in handling the long rods, piping, casting, and other fittings which have to be inserted perpendicularly. The borer or drill used is not much different from the ordinary hand arm of the stone cutters, and the blade is exactly the same, but is of massive size, three or four inches across, about four feet long, and weighing 100 or 200 pounds. A long solid rod, some thirty feet long, three inches in diameter, and called the "stem," is screwed on the drill. This stem weighs almost a ton, and its weight is the hammer relied on for driving the drill through dirt and rock. Next come the "jars," two long loose links of hardened iron playing along each other about a foot.

The object of the jars is to raise the drill with a shock, so as to detach it when so tightly fixed that a steady pull would break the machinery. The upper part of the two jars is solidly welded to another long rod called the sinker bar, to the upper end of which, in turn, is attached the rope leading up to the derrick pulley, and thence to a stationary steam engine. In boring, the stem and drill are raised a foot or two, dropped, then raised with a shock by the jars, and the operation repeated.

If I may hazard a further illustration of the internal boring machinery of the well, let the reader link loosely together the thumbs and forefingers of his two hands, then bring his forearms into a straight line. Conceiving this line to be a perpendicular one, the point of one elbow would represent the drill blade, the adjacent forearm and hand the stem, the linked finger the jars, and the other hand and forearm the sinker bar, with the derrick cord attached at a point represented by the second elbow. By remembering the immense and concentrated weight of the upright drill and stem, the tremendous force of even a short fall may be conceived. The drill will bore many feet in a single day through solid rock, and a few hours sometimes suffices to force it fifty feet through dirt or gravel. When the debris accumulates too thickly around the drill, the latter is drawn up rapidly. The debris has previously been reduced to mud by keeping the drill surrounded by water. A sand pump, not unlike an ordinary syringe, is then let down, the mud sucked up, lifted, and then the drill sent down to begin its pounding anew. Great deftness and experience are needed to work the drill without breaking the jars or connected machinery, and, in case of accident, there are grapples, hooks, knives, and other devices without number, to be used in recovering lost drills, cutting the rope, and other emergencies, the briefest explanation of which would exceed the limits of this letter.

The exciting moment in boring a well is when a drill is penetrating the upper covering of sand rock which overlies the oil. The force with which the compressed gas and petroleum rushes upward almost surpasses belief. Drill, jars, and sinker bar are sometimes shot out along with debris, oil, and hissing gas. Sometimes this gas and oil take fire, and last summer one of the wells thus ignited burned so fiercely that a number of days elapsed before the flames could be extinguished. More often the tankage provided is insufficient, and thousands of barrels escape. Two or three years ago, at the height of the oil production of the Bradford region, 8,000 barrels a day were thus running to waste. But those halcyon days of Bradford have gone forever. Although nineteen-twentieths of the wells sunk in this region "struck" oil and flowed freely, most of them now flow sluggishly or have to be "pumped" two or three times a week.

"Piping" and "casing," terms substantially identical, and meaning the lining of the well with iron pipe several inches in the interior diameter, complete the labor of boring. The well, if a good flowing one, does all the rest of the work itself, forcing the fluid into the local tanks, whence it is distributed into the tanks of the pipe-line companies, and is carried from them to the refineries. The pipe lines now reach from the oil regions to the seaboard, carrying the petroleum over hill and valley, hundreds of miles to tide-water.

A CEMENT RESERVOIR.

The annexed figures represent, on a scale of 1 to 50, a plan and vertical section of a reservoir of beton, 11 cubic meters in capacity, designed for the storage of drinking water and for collecting the overflow of a canal. The volume of beton employed in its construction was 0.9 cubic meter per cubic meter of water to be stored. The inner walls were covered with a layer of cement to insure of tightness.

A CEMENT RESERVOIR.

T is the inlet pipe, with a diameter of 0.08 m.

T' is the distributing pipe, and T" is the waste