SCIENCE NOTES & NEWS.

Franklin Times, Volume 9, Issue 721, 7 April 1922, Page 8

SCIENCE NOTES & NEWS.

A NEW SEARCHLIGHT. A portable military searchlight has been developed in the Italian Army, ■which is said to have several novel features. The motor-car which carries the searchlight as well as the generating equipment, is fitted with a thirty-horse-power motor. It is claimel that the new searchlight equipment enables the detection, of large bodies of troops at night quite as readily and at the same distances as in daylight, while the plant is invisible at only a few yards distance with the iris shut, even with the' searchlight working within at full power. WHY THE STARS TWINKLE. Although the twinkling of the stars is commonly referred to, they do not twinkle at all. The stars are really suns that throw out light, just as our sun lights the earth. When the rays of light from the Stars strike the air which surrounds the earth they have to pierce many little particles which are always floating about in the atmosphere. It is this interference between us and the source of light which gives the appearance of twinkling. On certain nights tlie light of th© stars will appear so bright and clear as to attract particular attention. This is because the air is so clear there is les3 interference than usual with the rays of light in reaching the earth. WOOD AND WATER. It is well known that all wood contains more or less water; even the driest wood contains two, or three pounds of water to every hundred pounds of weight. Absolutely dry wood is unknown, for the heat needed to obtain it would dissolve the wood and convert it into gas and charcoal. An eminent Swiss authority on the characteristics of wood believes that a sufficiently powerful and perfect microscope, could it be made, would show that the ultimate wood cell is composed of crystals iiks> grains of sugar or salt, and that thin films of water hold the crystals apart, yet bind them into a mass. A good microscope shows the wood cell and reveals its. spiral bandages and its openings and cavities, out. no instrument yet made reveals the ultimate crystals that, as uiaay believe, ho exist, an.i that wouui oxpiam why water cannot be expelled irom wood without destroying the wood itself.

A SC’JLPTOIi.’S I’XijUMA r IIC CHISEL. Lorado Taft, a Chicago sculptor, It is stated, lias installed in his studio a pneumatic chisel, by means of which the work of outlining marble statues is greatly simplified. The old method of carving with mallet and chisel is not only laborious, but rather awkward for the sculptor, since only one hand is loft free to guide the chisel. In the case of the pneumatic chisel both hands may be used for this purpose. The pneumatic chisel is driven by compressed air, at a pressure of seventy-seven pounds per square inch, operating through a flexible tube, the air being compressed in a large tank by means of an electric motor. The air passing through the tube has the effect of driving the chisel back and forth against the stone just as if it were hit by a mallet. The chisel, of course, is used only to outline the statue roughlyrthe finishing work all being done by band.