Democratic Sentinel, Volume 16, Number 19, Rensselaer, Jasper County, 27 May 1892 — POPULAR SCIENCE NOTES. [ARTICLE]

POPULAR SCIENCE NOTES.

—The recent discovery of prehistoriccopper implements on tho site of an ancient Indian village near Betterton, Md., Is considered as furnishing another link in the chain of evidence that among the most remote tribes there existed a system of intertribal trade. —Professor Duner of Germany has discovered that the revolution of the sun as shown by the movement at its equator is once for twenty-flve days and twelve hours of our time, while at or near its poles the revolution may be only once in forty-six of our days. This would only be possible with a movable and gaseous surface like that of the sun. —Long-distance photography is rendered quite successful by a new camera with a telescope objective, which consists of a concave lens of short focus and a convex lens of considerable length of foous. These are put at n certain distance apart, depending on the difference or the two foci. By the laws of optics this arrangement projects an inverted image of an object at a long distance from the lenses. —Herr Kllnge has been studying the eruption of peat bogs and the stream of dark mud these give out. He rejects the explanation that It is due to excessive absorption of water by the peat, or that it is caused by exploding gaseß, but attributes it to land slips of the ground under the bog, and remarks that in Ireland the eruptions are most frequent in limestone formations with caverns and bodies of underground water. —Future of Electricity.— The Electrical Review finds great promise in the future of the new eleotricity. It thus comments on the latest discoveries : “ Those who have followed the recent progress in the transmission of power will doubtless read with some awe the bold proposition made by Prof. Elihu Thomson for the transmission of power on a large Beale. Coming as it does from one of the best authorities in America, who differs from some others in that he usually accomplishes what he says he can accomplish, it can hardly be looked at as a wild scheme. When Prof. Thomson speaks of transmitting 130, 000-horse power 240 miles at 500, 000 volts through three wires about as large os a good-sized knitting needle, and to send tblß underground, too, through a small pipe, using only cotton ana cheap oil as the insulator, and then adds to this his opinion that it would be ‘practically^safe ’ —we cannot help admiring his courage. With such propositions mode in earnest, by a reliable authority, we may certainly look Upon the transmission of power as at present the most important of the numerous developments of eleotrical engineering. It is interesting to note, too, that the proposal is to accomplish this by means of three-phase alternating currents, such as were used at the Lauffen experiment. He also proposes to supply the central stations of a city like New York with cheap electricity instead of expensive coal. It is a curious coincidence that at tho same time another esteemed authority, Nikola Tesla, states that there will be no necessity in the future to transmit power to great distances, because we shall lie able to get cheap power—extract it, as it were—at any place in the universe. Electrical engineering is certainly making progress.”