Rensselaer Republican, Volume 19, Number 12, Rensselaer, Jasper County, 25 November 1886 — POPULAR SCIENCE. [ARTICLE]

POPULAR SCIENCE.

The eyes of poisonous snakes have been found by Dr. Benjamin Sharp to have elliptical. pSpflj, while in the harmless species they are circular. It is said that only about ono-third of the buried city of Pom pep has yet been unearthed. The Italian! Government is pushing the excavations with great vigor, -and very interesting remains are being constantly broughtllo light, / Dh. C. Keller, of Zurich, finds reason for believing that spiders destroy more aphides and insect enemies of trees than do all the insect-eating birds. His views have been verified by observations on coniferous trees, a few broad- leafed trees and apple trees. It is said that with a rock-salt lens photographs may be taken of a heated object (with a specially prepared plate) in the dark. For instance, a photograph could be made of a black-hot casting or stove in a dark room. This is because it allows artificial light to pass through it freely, while glass absorbs both" artificial heat and light. At the sea level, where the atmospheric pressure is about fifteen pounds per square inch',* water boils at 212 degrees F. At Argents, Montana, where the pressure of tho atmosphere is considerably less, the boiling point of water is about 200 degrees. On Mont Blanc it is 187 degrees. In a vacuum it is about 98 degrees, according to the perfection of the vacuum. Tiie carefully compiled list of Prof. C. G. Roekwood, Jr., reports seventyone American earthquakes for 1885;” five of the number being doubtful. Of the total the Canadian provinces furnished 8; New England, 5; the Atlantic States, 9; the Mississippi Valley, 3; the Pacific Coast of the United States, 34; Alaska, 2 ; Mexico, 1; Central America, 2; the West Indies, 2; Ecuador, 1; Peru and Chili, 3; the Argentine Republic, 1. Classified by seasons, 24 camein winter, 22 in spring, 14 in summer, and 11 in autumn. Among other successful mixtui-es in which to harden steel is the salt brine used in Sheffield. It seems that, as this mixture gets older, and from being constantly used, it improves its valuable qualities to such an extent that very often the water is sold at almost as dear a price as bad whisky. The idea seems to be that from constantly dipping the heated particles into the water, the air is driven ,out. In some cases these tanks are fifty years old, and are valued in proportion to their age. Mr. Graber lias recently described, in the transactions bf the Vienna Academy, the results of observations indicating that eyeless animals are sensible to light. In a box divided into compartments, and each furnished with two openings, he distributed equally a number of earth-worms. One of the openings in each compartment he obscured or concealed, and exposed the box to the light, examining the worms from time to time, and adding new ones every four hours. By repeated observations he found that they showed a decided tendency to withdraw to the darker parts of the compartments, only forty out of a total of 250 remaining in the light. He also studied the influence of different rays upon them, and found them susceptible to the, different Colors. When the openings were covered with blue glass, they manifested a marked preference for the red light.