As the temperature of water from great depths is invariably higher than that at the surface, artesian wells have been made to supply warm water for heating manufactories, greenhouses, hospitals, fishponds, etc. The petroleum wells of America are of the same technical description. These wells are now made with larger diameters than formerly, and altogether their construction has been rendered much more easy in modern times. Boring in the earth or rock for mining, geologic or engineering purposes is effected by means of augers, drills or jumpers, sometimes wrought by hand, but now usually by machinery, driven by steam or frequently by compressed air. In ordinary mining practice a bore-hole is usually commenced by digging a small pit about six feet deep, over which is set up a shear-legs with pulley, etc. The boring rods are from ten to twenty feet in length, capable of being jointed together by box and screw, and having a chisel inserted at the lower end. A lever is employed to raise the bore-rods, to which a slight twisting motion is given at each stroke, when the rock at the bottom of the hole is broken by the repeated percussion of the cutting tool. Various methods are employed to clear out the triturated rock. The work is much quickened by the substitution of steam power, water power, or even horse power for manual labor. Of the many forms of boring machines now in use may be mentioned the diamond boring machine, invented by Leschot, a Swiss engineer. In this the cutting tool is of a tubular form, and receives a uniform rotatory motion, the result being the production of a cylindrical core from the rock of the same size as the bore or caliber of the tube. The boring bit is a steel thimble about four inches in length, having two rows of Brazilian black diamonds firmly embedded therein, the edges projecting slightly. The diamond teeth are the only parts which come in contact with the rock, and their hardness is such that an enormous length can be bored with but little appreciable wear. Where do Dates Come From? Besides the dried dates which we are accustomed to seeing in this country, they are used extensively by the natives of Northern Africa and of some countries of Asia. It consists of an external pericarp, separable into three portions, and covering a seed which is hard and horny in consequence of the nature of the albumen in which the embryo plant is buried. Next to the cocoanut tree, the date is unquestionably the most interesting and useful of the palm tribe. Its stem shoots up to the height of fifty or sixty feet without branch or division, and of nearly the same thickness throughout its length. From the summit it throws out a magnificent crown of large feather-shaped leaves and a number of spadices, each of which in the female plant bears a bunch of from 180 to 200 dates, each bunch weighing from twenty to twenty-five pounds.