Democratic Sentinel, Volume 10, Number 17, Rensselaer, Jasper County, 28 May 1886 — POPULAR SCIENCE. [ARTICLE]

POPULAR SCIENCE.

A long serieb of determinations of the amount of carbonic acid contained by the air has been made at Liege, Belgium, the average result being 5.12;>8 by weight, and 3.352 G by volume in every 10,000 parts of the air. A meteorological station is about to be established among the h ghest mountains of Mexico, at an elevation of nearly 20,000 feet above sea level. As access to such a place is difficult, and often impossible, the recording apparatus will have to be made almost independent of human attention, and, as far as possible, all the instruments will be made to run a year without stopping. French experiments on the transmission of power by electricity have resulted less successfully than was hoped. Theoretically, the plan is feasible, but it is found to be more economical and practicable for manufacturing purposes to use the power directly at the source of supply. Modern railway facilities make it cheaper to transport goods than power, with its attendant loss of fifty per cent., not to mention its uncertainties. A member of the London Microscopical Society has described a case illus- ■ trating t e value of the microscope as a detective agent. Fraudulent additions were made to a bond, and the ink being darker than the original, the forger traced over the whole writing to give it a uniform shade. Under the microscope the difference between the original ivnd the added portion was clearly discernible, and the forgery was established. Commenting on Lieut. Greely’s discovery of coal within the Arcti; Circle in Greenland, Mr. W. Mattieu Williams expresses himself as dissatisfied with the preva ling nolion which demands a sub-tropical climate for the formation of carboniferous deposits. He has himself described the deposition of coal that is in actual progress at the present time in Norway, within four degrees of the Arctic Circle, and believes that similar deposits may bo found much farther i orth. No very violent alteration of climate, therefore, need be assumed to explain the Greenland coal. The principal astro omical event of 1886 will be the total eclipse of the sun on the 29th of August. The line of totality in this eclipse will cross the Atlantic Ocean, traversng land in the West Indies just after sunrise, and in Southern Africa toward sunset. On the coast of Benguela the total phase lasts nearly five minutes, and at Grenada, in the West Indies, the duration will be nearly four minutes. The comets of known period are expected to return during the year. Olbers’ comet, with a period of 71| years, will probably reach perihelion near the close of the year. A small comet discovered by Pons in 1819, and rediscovered by Winnecke in 1858, is due in 1885, as is also one first seen by Tempel in 1869, and again observed by Swift in 1880. The period of each of these two comets is about 5j years. i