Science Sittings

New Zealand Tablet, Volume 31, Issue 44, 31 October 1907, Page 35

Science Sittings

By 'Volt*

; Concerning the Ocean The oceans occupy three-fourths of the surface of the earth. A mile down the sea, the water has a pressure of a ton to every square inch. If a b^x 6ft. deep was filled with sea water, which was then allowed to evaporate, there would be 2in. of salt, left in the bottom of the box. Taking the average depth of the ocean to be three miles there would be a layer of salt, 440 ft. thick covering the bottom, in case all" the water should evap- ■ orate. In many places, especially in the Far North, the water freezes from the bottom upward. Waves are de--ceptive things. To look afc them, one would gather the impression, that the whole water travelled. This, however is not so. The water stays in the same place, but the motion goes on. In great storms waves are sometimes 40ft. high, and their crests travel fifty miles an hour. The base of a wave (the distance from valley to valley) is usually considered as being fifteen times the height of the wave. Therefore a wave 25ft. high, would have a base extending 375 ft. The -force of waves breaking on the shore is seventeen tons to the square foot. Air-ships Rudolph Martin, Imperial Councillor of Germany,' has recently made an interesting statement on aeronautics. ' Within ten years (he says) trans-Atlantic passages through the air, will have become a regular and 'normal method of journeying between Europe and America. The air voyages will 'be made in four days at a cost of fifty dollars for a first-class ticket. This is not the statement of an enthusiast, but is a sober statement based on scientific deductions. Only those directly interested know what giant strides have been made in the past few years in air-ships. The principle of air navigation has been solved, and the world is on the point of seeing the principal put into practical operation. The type of air-ship that will be employed for travelling between America and Europe, will undoubtedly be based, on the aluminum vessel of Count Zeppelinl It will have a cubic measurement of about 1,000,000 feet, will be from 600 to 700 feet long, and will be able to carry about thirty passengers. It will be able to' ma^e the distance between Hamburg and New York in 100 hours. Such an air-ship will cost about £75,000. to build. I may say that inventors are already figuring on the construction of such air-ships, and that how they will be navigated and successfully carried from shore to shore is already known to man. The air-ship, in my judgment has passed the experimental stage, and is now entering that of practical usage '. Trees that yield good soap Consul Guenther of Frankfort, reports the following interesting, item : Mr. S. Bertrand, chairman of the Algerian Agricultural society at L'Arba near Algiers, has succeeded, after nemerous experiments, in cultivating a large plantation of soap trees. From it are taken thousand tons of berries annually. The soap tree resembles an apple tree of medium growth. The fresh fruit is green, • the interior of wnich, besides the kernel, contains a yellowish gelatinous, , sticky substance. The fruit used for making soap contains three times as much soap as the ' panama ' wood. It seems destined to be of great service to the cloth and linen manufacturers, and, above all, for domestic purposes, as it can be used to clean linea and silken fabrics and colored embroideries. The colors are in this way renovated, whereas, the use of ordinary soap mV'es them run together. Big Concrete Bridge Span What is likely to be for some time, the longest concrete bridge span in the world, is that in a structure in Philadelphia, now being erected. The main span is to be 233 feet long, and 120 feet high, and, with four other spans, this bridge will have a length of 520 feet. Its breadth is 60 feet. In parts of the structure reinforced, concrete will be used, . but most of it, will consist of plain concrete, without any steel in it. The cost is to be over £50,000, and the work will be completed in' about a year. For the purpose of comparision, it is interesting to note that arches of masonry (not concrete) exist in Washington, having a length of 210 feet ; in Luxembourg, Germany, 275 feet long, and in Plauen, Germany, 295 feet long.

Money and friends are often synonymous. The worst of all faults is to have none.