Democratic Sentinel, Volume 17, Number 17, Rensselaer, Jasper County, 12 May 1893 — POPULAR SCIENCE NOTES. [ARTICLE]

POPULAR SCIENCE NOTES.

Cable dispatches are generally received at the rate of twenty to twentyfive words a minute. Au expert telegrapher of a land line sends about forty words in that time. We are accustomed to think of metals as incombustible; but the contrary is the case. With the exception of the socalled noble metals—gold, silver, platinum and a few others—all m9tals burn, or absorb oxygen when heated sufficiently in the air.—[Popular Science News. Sea fowls’ eggs have one remarkable peculiarity, they are nearly conical in form, broad at the base and sharp at the point, so that they will only roll in a circle. They are laid on the bare edges of high rocks, from which they would almost surely roll off save for this happy provision of nature. The Union Medicale gives a short account of the Pleurotus lux a fungus that takes its specific name from its property of glowing in the dark, even for twentyfour hours after it has been plucked. It lias lately been carried to Europe from Tahiti, where the women use it as au adornment in bouquets of flowers. Yankee "Windmills. —Prof. Robert 11. Thurston the dircctorof Sibley College, Cornell Univerity,has an article on “Modern Uses of the Windmill” in the “Engineering Magazine,” in which he says: “American Windmills,” like almost every other product of American ingenuity and skill, constitute a type quite different from the older forms original in Europe and the East. The latter all belong to the same species, consisting usually of four arms set at angles of 90 degrees, withsails covering but a small fraction. The American mills consist of numerous radial arms, and have sails set so closely together that, practically, the whole circle is covered. These sails are commonly wooden slats or blades, tapering from end to end, aud so set that they may intercept the whole current of air passing inside the outer circle described by their tips. They are so inclined as to deflect the air, as it passses among them, and absorb a considerable portion of its energy. Thus is formed a “screw,” somewhat resembling that of a steam vessel, but having a much larger number of blades. It is capable of giving vastly more power, and has a much higher efficiency than the old mill; though for stated power much smaller and lighter, and more “business-like” in appearance. Naturally this improved construction, for which credit is due to the American mechanic, is displacing its old rival, even in the home of the latter, and the “American” mill is now to be seen all over the world, —England, Germany, France. Holland, and their colonies on the opposite side of the globe, having all taken it up, as they have so many other of the fruits of the genius of the “Yankee” inventor, and with results most satisfactory to themselves no less than to the inventor. •