Rensselaer Union, Volume 7, Number 42, Rensselaer, Jasper County, 8 July 1875 — MECHANICAL AND SCIENTIFIC. [ARTICLE]

MECHANICAL AND SCIENTIFIC.

—An apparatus has recently been devised in France by which plates of glass may be safely and rapidly pierced by means of the electric spark. By the aid of this machine MM, Terquem and Taurein were enabled to pierce half-inch plate-glass at points near to one another without cracking. —Among the recent and novel schemes for securing a quick and comfortable passage across the Straits of Dover is that proposed by Dr. Lacomme. This gentleman’s plan is to lay a line of rails along tire sea bottom, but exposed instead of inclosed in a tunnel. Upon these rails a car’ or train of cars is to run upon the following phin: The engine is to be propelled by compressed air, while the cars are to consist of hermetically-sealed galvanized iron boxes. The air for the passengers will’be admitted in proper proportions by open supply-reservoirs and the whole train will advance through the water instead of on its surface as in the present steamboat.

—Dr. Scoresby gives the following interesting facts With regard to the length and height of ocean waves: The mean height of waves in tlie Atlantic, driven by a westerly gale, is eighteen feet. The greatest recorded height of a wave in the North Atlantic from the trough to the crest is forty-three feet. In northwest gales waves forty feet in height have been measured oil’ the Cape of Good Hope, while those oil’ Cape Horn were thirty-two feet. The velocity of ocean storm-waves in the North Atlantic is about thirty-two miles an hour, and that recorded byCapt. Wilkes for tlie Pacific Ocean twenty-six and onehalf miles. In an Atlantic storm the breadth of the waves, measured from crest to crest, is about 600 feet. —Observations upon the spots on the fluor of the crater Plato, on the moon’s surface, now show that decided changes have taken place—judged by the record of previous investigations—the streaks and colors of the -floor presenting unquestionable evidence in this respect. The shanges in the direction and luminosity of the streaks detected are, it is said, of such a character that they cannot be referred to changes of illumination, but depend, rather, upon some agency connected with tlie condition of the moon itself. The color of the floor has been found to vary as the sun ascends in tlie lunar heavens, being darkest with the greatest solar altitude. —The powers of carbolic acid to arrest fermentation and putrefaction are well known. But its odor is to most persons decidedly offensive, and if taken internally, even in minute doses, it is apt to produce very serious results. According to tlie recent investigations of Prots. Kolbe, Knap and others, salicylic acid possesses the same antiseptic power without the accompanying disadvantages. It is inodorous, of a faintly sweet taste, and can be taken internally, even in relatively large doses, without" injurious effects. It will, therefore, prove of great value in preserving meat, eggs, fruit, preserves, beverages, medicinal preparations, inks, and a great variety of organic matters from moldiness or putrefaction. One part of rhe acid is capable of preserving 26.000 parts of water from being tainted.