SCIENTIFIC & USEFUL.
AHTS OF PECULIAR TASTE. Residents in India are appealing to entomologists to diecover some means of circumventing; the white ant. Thin insect would appear to have a peculiar appetite for wills, a recent law suit having hinged upon the loss of such a document in this manner. An advertisement in the Gazette of India also reveals the fact that no lees than seven Government promissory notes, of the aggregate value of 3500 rupees, have been devoured by white ants. ABOTTJBTJS. Dr* Elkin, the astronomer of Yale University, and formerly of the Cape of Good Hope, has, by a long serieß of observations on the Parallax of the star Arcturus, arrived at the conclusion that it moves with the inconceivable velocity of 221 miles a second — that is to say, it would traverse the dietance from London to Edinburgh between two ticks of a watch. This in 21 timeg faster than the speed of the earth in its orbit round the eun. Dr. Elkin also finds that Arcturus is so far away from us that his light, travellihg 190.00 C : miles a second, takes 181 years to reach us. A lONG ELECTEIO BAILWAY. They are discussing & big electrical enterprise in the dominions of the Czar, the notion being nothing less than the construction of an electric railway between St. Petersburg ond i Archangel. If it should be carried into effect., Russia would, of course, have the longest electrio railway in the world, the dietarjce beiDg more than 800 kilos. The current would be furnished by a series of generating stations distributed along the line. Meanwhile it is announced that an electrical exhibition, organised by the Imperial Polytechnic Society of Russia, will-b^eW in St. Petersburg, and will remain opfcn until 'March, 1892. ' \
AN AMPHIBIOUS VESSEL.. | A steamer which can be propelled on land by menns of its own engine hss just been con- , struoted at the Ljung^ren Engineering Works at Krißtiansstad, in Sweden. It is intended for the traffic on two lakes close to Boras, whioh, however, are separated by a strip of ' land. Hails have been laid between the two ; lakes. The steamer, which has been christened ! very appropriately Svanen (the Swan), can run itself across from one lake to the other. ' At a trial trip, if one may cull it so, at the ' works, the vessel fulfilled the tests very well. 1 The engine is 10-horee power, and the Svanen ; can accommodate some 60 passougers. NATCTBAL LENGTH OP HUMAN LIFE. i Dr. Ebstein, of GoetMngen, in a discourse I on this subject, says :— The question as to the natural duration of life is first to be answered. According to the latest discoveries, the average length of life in the natural order of things, is from seventy to seventy-five years. Women live somewhat longer than men. The mortality among children, particularly less than a year old, iB very great. From the ace of puberty till the fiftieth year the death-rate is small ; from that time it becomes greater each year. Too great an old age iB a questionable blessing, because a renewal of youth can be reached in no way whatever. It is evident, therefore, that the normal limit of the age of man is that which is attained without bitter breaking down and suffering. POWER AND VOICE OF THE BEE. In a recent work on the bee, Mr T. W. Cowan states that the inspctcnu draw twenty times its own weight, can fly more than four miles an hour, and will seek food at'a distance of four miles. By a beautiful mechanical adaptation its wings bear it forward or backward, with upward, downward, or suddenly arrested course. Its threefold voice organs are the vibrating 1 wines, the vibrating rings of the abdomen, and a true vocal apparatus in the breathing apparatus' or spiracle. The buzz is produced by the first two, and the hum, whioh may bo "surely, ,, cheerful, or colloquial significant," by the vooal membrane. A number of bee's notes have been interpreted. "Humm " ip the cry of contentment;, " wuh-nuh-nuh" glorifies the egg layings of the queen, "Bhu-u-u"is the note of the young bees at play, "s-s-s-9 " means the muster of a swarm, " b-r-r-r " the slaughter or expulsion of the drones, and the "tn-tu-tu" of the newly hatched young queen is nnsweved by " qua-qua-qua " of the queens still imprisoned in their cells. ADAMANT STONE. Artificial ftone has hitherto been made by mixiag in certain proportions broken granite or other stone or materials with Portland cement and water, after which the slab or block is placed in a solution of silicate of soda. This method requires, from the time of mixing until the stone h ready for uso, a period of two or three months. A new process, by which stone can be prepared in one week, is now being introduced by the Adamant Stone Company, 101 Leadenhull Street, EC. At a demonstration of the method of manufactoro. it was shown by experiments in a hyrlraulin prees that adamant stone can withstand exactly twice as much pressure bs Victoria stone, but no information was forthcoming as to durability. Adamant Btono consists of two parts of fine crushed Aberdeen granite and oae part of Portland cement mixed with water. After mixing, the material is placed in a mould, and then forced by a ram into a hydraulio press. Here most of the water is expelled, and the slabs formed into a compact mass. The slabs are then allowed to dry for a week, when they are said to be ready for use. — Mechanical World. THE CAMEL. In a recent paper on the cntuel, Herr Lehmann refers, among other things, to its relations to temperature and moisture. Neither the most broiling heat.; nor the mosb intense cold, nor extreme daily or yearly variations hinder the distribution of the camel. It seems, indeed, that the dromedary of the Sahara has batter health there than in more flbuably warm regions • though, after a day of tropical heat, the thermometer sometimes goes down Severn 1 rlegresa below freezing point, and daily variations of 33°7 C. occur. In Seruipalatinsk, again, where the camel is found, the annual varia'ion of temperature sometimes reaches 87 O> 3. In Eastern Asia, winter is tbo time the animals aro made to work. In very intense cold, they are sewn up in folt covers. Camels ore rery sensitive to moisture. In- the region of tropical rains they are usually absent, and if they come into such with caravans, the results of the rainy season are greatly feared. The great, humidity of the air explains the absence of the camel from the northern slopes of the Atlas, and from well-wooded Abyssinia. This sensitivoness expresses itself in the character of different races. The finest, moct, noble-looking camels, with short silk-like hair, are found in the interior of deserts (as in the Tuarek region, in North Afric.*), and they cannot be used for journeys to moist regions. Even in Fezzan (south of Tripoli) the animals are shorter and falter, with long, course hnirj and in Nile landß and on coasts it is the Fame. These, animals, too, are less serviceable as regards speed and endurance. Herr Lehmann states it as a law that the occurrence of the camel finds its limits wherever the monthly average vapour tension in the air exceeds 12 mm. — Nature.
AN AMPHIBIOUS VESSEL,
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SCIENTIFIC & USEFUL., Mataura Ensign, Volume 15, Issue 1162, 26 February 1892
SCIENTIFIC & USEFUL. Mataura Ensign, Volume 15, Issue 1162, 26 February 1892
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