New Crane.
A crane for raising weights, on an entirely new principle—that of the application of the lever, assisted by wedges, instead of the usual plan of wheel and pinion, for multiplying power—has recently been constructed at the West India Docks. The power of two men, with the patent crane, is stated to be capable of lifting from 2-1/2 to 3 times the weight lifted through the same space in a given time, by the best constructed cranes on the old principle of wheel machinery.
Etching on Ivory.
The usual mode of ornamenting ivory in black, is to engrave the pattern or design, and to fill up the cavities thus produced with hard black varnish. Mr. Cathery has much improved and simplified the process, by covering the ivory with engraver's varnish, and drawing the design with an etching needle; he then pours on a menstruum, composed of 120 grains of fine silver, dissolved in an ounce measure of nitric acid, and diluted with one quart of pure distilled water. After half an hour, more or less, according to the required depth of tint, the liquor is to be poured off, and the surface is to be washed with distilled water, and dried with blotting paper. It is then to be exposed to the light for an hour, after, which the varnish may be removed by oil of turpentine. The design will now appear permanently impressed on the ivory, and of a black or blackish brown colour, which will come to its full tint after exposure for a day or two to the light. Varieties of colour may be given by substituting the salt of gold, platina, copper, &c. for the solution of silver.—Trans. of the Society of Arts.
Geology.
Among the fossil bones lately dug from under the lava of the mountain of Boulade, in the neighbourhood of Issoire, in France, none have been discovered belonging to the human body. The same is the case in the other mountains of the vicinity. But, although there are no human bones, in several places, and especially in the mountain of Boutaresa, (which is not far from the mountain of Boulade,) pieces of wood have been discovered, buried under the ancient lava, which observers worthy of credit declare seem to have been fashioned by the hand of man, and to have been cut with a hatchet, although rudely, and as might be expected in the infancy of the arts. Did man exist then, at that remote period when elephants, lions, and tapirs, lived in Europe, with rein-deer and bears? This is an exceedingly difficult question, and one which hitherto does not, by any means, appear to have been satisfactorily resolved.—New Monthly Magazine.
THE MONTHS.
