SCIENTIFIC MISCELLANY

Otago Witness, Issue 3757, 16 March 1926, Page 79

SCIENTIFIC MISCELLANY

(Fob tbb Witness.) PRECISION IN ESTIMATING RIPENESS. For thumb pressure in testing the ripeness of fruit the United States Department of Agriculture has substituted a more accurate device in which the pressure required to give a plunger a certain penetration into the fruit is registered by a gauge. The record indicates the state of ripeness or greenness TREES IN ICE STORMS. A species of catalpa is found by Trofessor Walter E. Rogers, of Lawrence College, Wisconsin, to be most resistant to winter ice storms, and spruces, pines, and oaks follow in the order named. Among the trees most damaged by the ice-load accumulated on their branches were elms and poplars. ONE SOLUTION OF THE GARBAGE PROBLEM. In the Los Angeles garbage disposal experiment, which has continued about four years, the waste is the only food of 40,000 hogs. Gondola cars take the garbage 50 miles to the hog ranch, wh'ere concrete floors make it possible to prevent accumulation of rotting material and providing breeding places for rats. TRANSFUSION IN TREES. Insecticides applied by transfusion are claimed to have given promising results in California experiments. Ferrous sulphate solution was used to combat certain insect and blight diseases of trees, and was led from a bottle near the top of the tree by a hose to a glass tube passing nearly through the trunk. The liquid was gradually distributed in the tiee’s circulation. The health of diseased trees appeared to be improved, and the application is reported to have been followed by heavy fruiting in some trees. GROWTH OF IRON. The growth of cast iron under alternate heating and cooling, a minor trouble in easily-replaced grate bars, has become a serious matter with the development of high-pressure steam Renewal of a steam turbine casing is troublesome and expensive, and slight enlargement of an internal part may add much damage to the cost of replacement. The growth has been traced to internal oxidation around the graphite of the iron. The microscope shows an apparent unusual proportion of graphite, but the graphite particles have been really largely replaced by gases penetrating the iron. The process is very slow when the heating is continuous instead of intermittent.

AMERICA’S FUEL. Considering the fuel resources of the United States from data presented to the Affiliated Technical Societies of Boston, F. H. Daniels finds that in heating value the coal remaining is 1370 times the remaining oil. Of petroleum 42 per cent, has been used, with 8,500,000.000 barrels remaining. The anthracite coal remaining is placed at 17,000,000,000 tons, 15 per cent, of the original supply having been used; the bituminous left equals 1,510,000,000,000 tons, less than 1 per cent, having been mined; lignite is available to the amount of 2,000,000,000,000 tons, this store being practically untouched. THE LOST METEORITE. The Ahnighito rr teorite, brought in 1897 from Greenland to New York by Lieutenant Peary, weights 36$ tons, but it was a vastly greater one that excavated the huge crater, half a mile across, at Canon Diablo, Arizona. While it was early suggested that this marks the site of an extinct volcano, no evidence of volcanic action could* be discovered. The many fragments of meteoric iron found in the vicinity, some of them weighing several hundred pounds, seemed to establish the cause of the crater, but the failure of vertical borings to locate the main meteoric mass was very mystifying. In 1909 Daniel M. Barringer, of Philadelphia, discovered, as he believed, that the meteorite entered the earth at an angle of about 45deg. Drilling at the point indicated by this theory has brought results regarded as successful, but instead of the expected rich mine of metallic nickeliron has shown only the meteorite’s decomposed remains. The original material was made highly oxidisablc by the presence of a little chlorine, so that most of it may hafe been converted into magnetite or hematite. The boring has revealed no metallic iron, but has shown ccnsiderable iron oxide carrying nickel. THE BIGGEST LAND ANIMAL. Of all wild animals the elephant is the best known and the least known is the paradoxical assertion of Major W. R. Foran, in Chambers’s Journal. The elephants seen in captivity are Asiatic specimens, and even the very largest are undersized. The African and the Asiatic varieties differ as much from each other as they do from the mammoth and similar extinct forms that existed in the Stone Age. The African is nearly

or fully twice the size of the Indian elephant, standing nearly or fully 13ft in height. The African species is not only larger but more savage than the Asiatic, i.nd the majority of hunters seem to agree that the African elephant i j the most dangerous of all big game animals to hunt. Unlike his Indian kinsman, the African el pliant has been tamed and trained to man’s uses. Six or more surprising facts may be stated. First, a cow elephant is always the leader of a herd; second, bull elephants are always the nursemaids and ir' . the babies; third, ail elephant is one of the most intelligent of all living creatures; fourth, elephant herds have a regular system of signals; fifth, it is the cow and not the bull elephant that is the fighter >f the family; and, sixth, i‘ seer? certain that the days of the elephant in Africa are numbered. Now that the elephant is suspected of being a carrier of sleeping sickness, its extinction cannot be ar distant, though its passing will be a veritable ana most tragic calamity. THE WORTH OF TUNGSTEN. Considering the tremendous effect of tungsten on modern industry, Zay JelT’-ics, in his late address to the American Society of Mechanical Engineers, noted that it : s the principal alloying element in high-speed steel, and that since the development of this alloy, in the present century, the mechanical arts have been literally revolutionised. It would be impossible to determine the economic value of high-speed steel. Another of the applications of tungsten is of ’ ery great importance, however, and it is possible by certain assumptions to assign to this a relative money value. The average present efficiency of a tungsten-filament incandescent lamp is four and one-lialf times that of a carbon filament lamp. Without considering miniature lamps the electric energy consumer annually for illumination in the United States alone is over 15 billion kilowatt-hours, and the cost to the consumer is approximately 800,000,000d01. If the same level of illumination w r ere maintained by carbon lamps, assuming the same average cost of electrical energy, the additional expenditure necessary -would be about 2,900,000,000d01. If we were getting from carbon lamps the present level of illumination, assuming that w T e have no other material besides tungsten to replace the carbon, we could pay about 330,000d0l a lb for tungsten without increasing the cost of the light. The actual coat of the tungsten in the ore at the present time is less than Idol a lb.