SCIENCE NOTES.

Otago Witness, Issue 3149, 22 July 1914, Page 68

SCIENCE NOTES.

Experiments have shown that of three wires ‘of tho same thickness one made of gold will sustain 1501 b; one made of copper, 3021 b; and one of iron,. 5491 b. Magnetism Affects Strength.— Mr W J. Crawford seems to have proved by experiments at the Technical Institute of Belfast that magnetism affects the strength of iron and steel Ho used bars of mild steel and wrought iron, Bin long by 3-sin to lin in diameter, part of them being kept at magnetic saturation in a solenoid, and in the testing machine the elongation of the magnetised pieces was decreased 3 to 16 per cent., while tho average breaking load seemed to be increased. Rudder as Brake.— A new ship’s rudder, recently tried with satisfactory results on motor boats, is in two hinged halves, opening like a book. When closed it is an ordinary rudder; but when the wings are open, the water from the corkscrew action of the propeller strikes the flat service, which acts so powerfully as a brake that the boat can be stopped with the engines still racing full speed ahead. When the rudder halves are opened a little more, so as to incline forward, the vessel actually begins moving astern with the, propeller still running ahead. Peat Dust as Engine Fuel. — Tho fact that Hi von Porat, a Swedish engineer, has discovered and perfected a process for utilising peat powder as fuel for locomotives has awakened great interest in Sweden, and a number of the railways in that country are preparing to use this new material instead of coal. In the von Porat system the peat powder js fed by an automatic process into the furnace of the locomotive, which is specially arranged to consume it. Of his system Mr von Porat says: “ The same results can be obtained from one and a-half tons of peat powder as from ono .ton of coal. As to firing, the work is almost nothing in comparison with firing with coal, because the powder is forced into the furnace by automatic process. Another advantage is that no cold air can get into the firebox, and neither smoke nor sparks escape from the smokestack.” For Physicians and Nurses.— A new pulse-counting watch, which has been designed for physicians and nurses, shows, without calculation, the number of pulse-beats per minute, and has the advantage of strict accuracy and of not requiring the attention to bo fixed on the watchhands. Its principle is that of the stopwatch. Pressing a push-button sets in motion a largo second-hand when counting of the pulsations begins, and at the twentieth another pressrirc on the button stops the hand. The number of beats per second is then indicated on the dial. Again pressing the button sots the hand at starting-point, and the watch is ready for another determination. Besides this use, the apparatus is also adapted for automatically recording any observations in minutes, seconds, and fifths of a second. The Flight of tho House-fly.— At a recent meeting of the Cambridge Philosophical Society Dr E; Hindle described some experiments which he made with G. Merriman in order to determine the housefly’s range of flight. During the course of .the experiments about 25.000 flies were released under various conditions of weather and temperature. No fewer than 50 observing stations wore arranged where tho flies were caught in traps or on flypaper. In order to identify them they bad been dusted with red or yellow chalk powder. Tho experiments showed that the flies winged their way cither directly against the wind or obliquely to it. The phenomenon has also been observed in the case of other issocts as well as of birds. The greatest distance covered by a fly was 700 metres (nearly half a mile), and a large part of this lay over open ground. In densely-crowded cities, Dr Hindle does not believe that the fly travels more than 400 metros (a quarter of a mile). In order to secure the widest distribution, fine weather and ■ warmth are necessary. Flies which were released in the afternoon were not so widely distributed as flies which wore released in tho morning. Radium in the Upper Atmosphere.— Hess, of the Vienna Radium Institute, has recently published the results of some remarkable experiments. Ho has investigated the penetrating radiation which occurs in tho upper atmosphere by means of balloon ascents, and he arrives at tbo startling conclusion that at a height exceeding 2000 metres there is a rapid increase in the intensity of tho penetrating rays. At these heights the penetrating rays from the earth itself would be absolutely negligible, while that ir< m the radium emanation in the air, which has its origin in the earth and is ct limited life, must be, at any rate, less than at tho surface. So that it would seem we must assume some extra-terrestrial source

for these radiations. The conclusion that a great part of the penetrating radiation cannot come from the known radio-active constituents of the earth and atmosphere is one that must evoke general interest, and calls for the further radio-active cxplorat'on of the upper atmosphere. —An Electric Lock. — A.n electric lock has been invented which indicates when it is being tampered v th. The mechanical details arc so arranged that it is impossible to pick the lock without causing an alarm to be sounded. If anything except the proper key is used, the slightest pressure upon the central pin of the lock closes an electric circuit; and even with a, key of non-insulating material the alarm is given. The alarm can also be set to give warning whether the lock is being opened from the outside or the inside, and the latch likewise can be made to give the alarm. The burglar may search for the wires, but this will be vain, because the circuit is completed by way of the hinges, so that there are no visible wires he can cut. This ingenious lock is the invention of a Frenchman, but it is also produced in England. Electric Hot and Cold Air Producer. — An electric tool has been devised for the purpose of accelerating the process of drying. In appearance it somewhat resembles a revolver, and is about the same size. The heating element is inserted in the barrel when hot air is required, and the stock contains a very small but powerful electric motor which drives a rapidly-revolving fan, the whole mechanism being so designed that oiling and attention are unnecessary. A length of flexible wire extending from the handle to a plug is connected to an electric lamp socket or coupled up to an accumlator, and directly the switch is moved an intense current of hot or cold air is generated and projected in a continuous stream until the drying is effected. The applications of the apparatus are practically unlimited, as it can bo used wdionever a current of hot or cold air is required. For medical purposes it is invaluable, especially for vibratory massage. The Failure of “Hail-rods” in France. — Reference has been made several times to the recent erection in many parts of France of large lightning-rods, known as ‘‘electric Niagaras,” supposed to be efficacious in averting hailstorms. The futility of such devices seems obvious to persons familiar with the mechanism of thunderstorms, of which hail is merely a by-product, yet hundreds of the rods have been installed at great expense. In a recent communication to the National Society of Agriculture of France, Professor Alfred Angot, director of the French meteorological service, after pointing out the absurdity of the “Niagaras” from a scientific point of view, cited a number of instances in which the reds had signally failed of their purpose. Thus, the large rod installed on the Eiffel Tower has not had any effect on the frequency of hail in its vicinity. In the,suburbs of ClermontFerrand a big “Niagara” stands on an iron tower 100 ft high. This rod was itself pelted with hail twice in 1912, and four times in 1913; in one storm some of the hailstones attained the size of hens’ eggs. Similar cases have been reported from other parts of France. —The Tails of Comets.— For some time the luminosity of oometary appendages has been attributed to electrical phenomena , analogous to those which take place when a tube of rarefied gas is traversed by an electric discharge. But this rather vague explanation took the second place when Arrhenius came forward with the theory that the tails of comets are due to the pressure of radiation from the sun. But another explanation has been offered recently -which is, from some points of view, more satisfactory. The nucleus of a comet is regarded as a permanent source of electrons which are projected into the cometarv atmosphere. If now the electric field of the sun is centripetal, the luminous effects, duo to the projected electrons, should be localised in the direction opposed to the sun. From researches made on the magnetic field of the sun, and applying the theory of Schuster, which attributes the magnetism to electric charges carried round by the sun’s rotation, it appears that the dominant electric charge on the sun should bo negative, which results in a centripetal electric field ; thus, the above hypothesis accords with the most recent discoveries. —Made from Milk.— Recent notable developments in the production and industrial use of casein form the subject of an interesting report from a consul, Mr W. H. Hunt; stationed at St. Etienne, France. Casein, which is the principal proteid of milk, is now obtained by electrolysis, according to the following recently invented process. In the middle of a largo vat full of skimmed milk heated to a temperature of 80 deg C., a porous vessel is placed containing 5 per cent, solution of caustic soda; an iron cathode is plunged into the soda, and a rod of carbon, serving as an anode, into the milk. An electric current sets free the phosphoric acid contained in the milk, and the casein precipitates. As compared with the method of obtaining casein by the use of acids and rennet, the cost of this process is very low, the yield is greater, and the casein produced contains no foreign ingredients. Vegetable casein, now produced on an extensive scale from the soya bean, can be put to the same use as animal casein. The principal use of casein is in the manufacture of galalith (milk stone), used as a substitute for ivory, tortoiseshell, celluloid, etc. Penholders, purses, frames, phonograph discs, and a great variety of other articles are now made of galalith. It is also used as a chemical fertiliser.