SCIENCE and INVENTIONS.

New Zealand Herald, Volume LVI, Issue 17151, 3 May 1919, Page 3 (Supplement)

SCIENCE and INVENTIONS.

NEW USB FOB PERISCOPE.

The orchestra pit in some theatres ie under the stage, yet the demands of certain plays, for example, pantomimes, require that the musical director shall watch the stage and direct his orchestra so that the music synchronises exactly with the movements of the actors. The difficulty is being solved by the use of a trench periscope, permitting the orchestra conductor to follow the movements of the players from his seat under the stage.

MAST TURNING LATHI. Heretofore masts have had to be shaped by hand, a task which is very laborious and requires skilled workmen. Recently, however, a machine has been designed which will shape masts up to a hundred feet in length and three feet in diameter. The timber is set up in the machine and revolved at a speed of 50 revolutions per minute, and it ie shaped by a cutter head which is electrically driven at the rate 08 700 revolutions per minute. This cutter head is mounted on a carriage which is moved along the timber against a rail set to give the proper profile to the mast.

BREAD FROM COTTON SEED. A highly nutritious flour suitable for human consumption can be produced from the residue of the kernel of tho cotton seed after the oil has been extracted. This flour, it is-stated, has been commended by the United Slates Government as a dilutent for wheat, and ib being manufactured in large quantities in the States. By judicious use of cotton seed flour, a wholesome and palatable bread can be made, possessing the same nutritive properties as the all-wheat loaf, and effecting a considerable reduction in the actual quantity of wheat flour used. ,

TANKS TO FARM TRACTORS. The little lightweight Renault "tanks" established an enviable reputation as fighting machines during tin last year of the war, and now, in times of peace, they promise to become equally useful. Already some of them have been converted into agricultural tractors, by the removal of the guns and armour, and a few other alight modifications, and are said to be doing excellent service on the farms of France, where labour is painfully scarce just now. Another, and probably temporary use, that has been found for them is towing barges on canals, taking tho place of horses.

CHEAP FUEL. Tho search for a fuel that will be cheaper than petrol, and equally as efficient, so far, appears to have attained no satisfactory result. Tests of the latest widely heralded fuel, which appears to bo 'only a mixture having benzol as a base, do not seem to bear out the claims made for it; and, indeed, similar mixtures have been experimented with for at least five 1 rears in England without any very practical results. Undoubtedly benzol, either 1 alone or combined with other inflammables liquids that can be vaporised or properly atomised, will form a valuable addition to our fuel supplies, but there is little probability that these compounds will supplant petrol.

I THE ?OHB OT THE AIR. A most important development is. the production of a low-priced, most useful aeroplane, which is the equivalent of a Ford automobile It is a very attractive little machine, equipped with a 40 horsepower engine, capable of carrying two passengers at a speed of from 70 to 80 miles an hour. A moat remarkable feature is that this aeroplane will make about 22 miles on a gallon of petrol. Having a span of only 18 feot, and weighing only 350 pounds, complete with motor, and having a landing speed of only 37 miles an hour, this plane can land on and start from almost any country road. It is expected to sell at about £400.

NATURAL GAS GUSHES. Right op in the wilds of Athbasca, on the river of that name, in North-West Canada, here is a natural wonder— gas "gusher" shootine eighty feet of flame up into the ;ur. No one knows who first nt a light to this flow of natural eas, but records would show that it has been burning continuously for the past twenty years. Experts declare that four million feet of rifiural gas is consumed every twenty-four hours by this strange prairie fire. Some day, when civilisation advances into this hitherto unsettled rogion, the "as will be harnessed and used for lighting, heating, and power purposes, as is done at Medicine Hat, much farther south, where' natural pas has been tar? c d- Indeed, the city authorities of Medicine Hat find it cheaper to allow gas to burn all day in the streets than to turn it out.

FISH STOPPED BY ELEOTRIOY. Where rivers from which fish are taken in large quantities are used for irrigation, an on the Pacific coast of North America, a huge loss takes place through millions of the young fish passing into the irrigation channels and thence on to tne land. It was found however, that by placing a metal plate or rod at each side of a channel and passing an alternating electric current between them, the intervening water became highly charged with electricity. One nair of such electrodes alone is not entirely effective; but several paiis placed at intervals, with electric currents progressively increasing in strength, completely stop the fish from getting past. Presumably the fish, finding the shocks grow stronger and stronger as they proceed, are at length induced to turn back. The amount of current used is very small, and the cost of working the apparatus almost negligible when compared with the saving in (ten.

ELECTROLYSIS IN CONCRETE. The suggestion is made by a French scientist that the deterioration of reinforced concrete may be caused by spontaneous electrolysis. The theory is that dampness and chemical impurities in the water employed in the manufacture of the concrete give rise to a continuous flow of local current which slowly corrode the metal, and, little by little, cover it with ;i layer of oxido. Tho metal framework thus increases gradually in volume, 60 as finally to exert sufficient pressure to cause cracking and bursting. That this pressure may be very formidable is proved by the following experiment. A column of cement, 30 centimeters high and 150 millimeters in diameter and having an iron core running from one end to the other was plunged into water. A 50-volt current was then passed through the iron core, which acted as the anode; in less than three hours the .column of cement had entirely collapsed.

AIRSHIP PARACHUTES. A solution has boon found of tho problem of bow to "drop" airship passengers at intermediate destinations, without incurring the serious loss of gas involved in the vessel's own descent. A ribbed parachute has been devised with a diameter of some 60ft—an area of silk capable of sustaining the weight of half a dozen human beings., who instead of being harnessed to ropes, as in the ordinary style of parachuting, , will be comfortably carried down in a basket. Recent experiments have demonstrated the feasibility of steering parachutes; and so an experienced aeronaut will be in charge of each load of descending passengers, to obviate the risk of cornin? in contact with any projecting object. The omnibus parachute follows lines of construction which admit of the canopy being outstretched by moans of its ribs before parting company with the airship, which will meanwhile havo had its engines stop-, ped. This will eliminate the hitherto necessary " free drop," namely, that first stage of the fall, covering 80ft, or more, when the silk canopy is unfolding and expanding to arrest tua velocity