Science Siftings

New Zealand Tablet, 6 March 1913, Page 53

Science Siftings

By « Volt.'

A Clock Made Entirely of Glass. A clock constructed throughout of glass is the result of six years' work on the part of a Bavarian glass polisher. The plates and pillars which form the framework are of glass, and are bolted together with glass screws. The dial plate, hands, shafts, and cogwheels are of glass, and glass wedges and pins are used for fastening the various parts of the running gear together. Like the clock itself, the key by which it is wound is of glass. The construction of this remarkable timepiece was a matter of infinite pains. Some of the parts had to be made as many as forty times before a clock that would go could be produced. A Telephone Three Miles in the Air. The station, said to be the highest in the world, is in the meteorological observatory on the top of Mont Rosa, in the Pennine Alps, 15,450 feet above sea level. At this elevation snow is always found, and advantage is taken of the high insulation given by dry snow, the wires in the last section, at the peak, being simply laid on the snow-covered ground. To prevent breakage by glacier movements, the line is carried through rings on the telephone poles. The poles are short, and are taken down at the end of every summer season and replaced at the beginning of the following summer. Wireless Telegraphy in America. The United States Government's latest achievement in aerial telegraphy has been declared a success. The plant, located at Fort Meyer, Arlington Heights, Virginia, claims to be the most powerful wireless station of the world, having a sending radius of a least three thousand miles. The antennae swing from three towers, which are, one 800 and the two others 650 feet above mean sea level. The workrooms have been rendered sound-proof, thus increasing the efficiency of operation. According to official report, the total number of radiotelegraphic stations along the Atlantic and Gulf coasts, the North Pacific Ocean and Alaska is 136. Of this number seventy are under the control of the Government. Those of the Philippine Islands, ten in number, are superintended by the Jesuit Fathers connected with the Philippine Weather Bureau. Air. Three things are essential to life: air, water, and food; and the order in which these are named expresses their relative importance to life. Composition Pure air is a mixture composed of two gases—oxygen (one part) and nitrogen (four parts). Air is most important, since we can live only a few minutes without it. The air we breathe carries oxygen into the lungs, keeping the blood red and pure. The body contains carbon, so when oxygen is inhaled it unites with the carbon, burning up the waste matter in the body, thus producing the heat which keeps the body warm. The burnt out air contains carbon dioxide and is exhaled. If you should sit in a very small room that had no fresh air supply, how would you feel after the air in the room had been.used up? Why? What is meant by ventilation? Why is good ventilation necessary? The air becomes impure in a room by the carbon dioxide given off from the lungs, from lamps, from gas stoves, etc. In a small quantity from coal stoves (although in this case most of the carbon dioxide passes into the chimney). Anything that uses up the oxygen in a room or which allows too much breathed air to remain in the i room makes air impure. Decaying vegetables and water • that have been allowed to stand for a length of time in cellars may fill the room with impure air and cause disease.