MODERN SCIENCE.

New Zealand Herald, Volume LX, Issue 18577, 8 December 1923, Page 4 (Supplement)

MODERN SCIENCE.

ITEMS OF INTEREST.

WORLD'S RADIUM SUPPLY.

FUTURE PRODUCTION.

The world's supply of radium is now placed at 200 grammes and the - uranium ores of the Belgian-Congo—discovered in 1913 and 1915— believed to be capable of producing 25 grammes a year for the next ten years.

NOVEL USE 3POR LIQUID AIR. Liquid air has been found an effective aid in cracking the hard-shelled nuts used for producing oil. Dipped for a moment into liquid air, the shells become so brittle that they are easily broken, and the oil is then readily extracted. The quality or flavour of the oil is not- affected.

NEW IMITATION LEATHER. A new plastic material for book covers and like purposes produced on the uontinent is a mixture of rubber with such waste as sawdust, leather buffings, ground shavings and shoddy. The material can be dved anv colour. It has advantages over "leather in greater cheapness and durability, and it is'adapted for producing a much wider range of effects.

MAGNETIC ASSAYING. A device bus been perfected for quickly reducing a sample of ore so that the magnetic. iron percentage can be accurately computed. A sample of -ore is placed in the glass tube which has been previously' filled with water. The carnage and tube are then automatically rocked, the carriage bearings being placed at the poles of the magnet. A stream;- of: Water passes through the tube, washing away the tailings from the concentrate, which is held at the poles. When the washing is completed, the magnetic assay 'is made.

RADIO WHILE THEY SLEEP. The instructors of the United States Navy iiave had difficulty in teaching the radio code to some of their students. Apparently certain minds could not memorise the tricky dot's and dashes as well as others. Many students were at their wits' end till someone hit on a brilliant

idea. The sub-conscious mind has a memory 99 per cent, perfect, whereas the conscious mind is very poor in that department. While man is asleep the sub-conscious is dominant, the conscious being out of the way for the time being. Well, then, said the instructors, put the men to sleep with the 'phones on their ears and send them code while they slumber. When they wake up they will know it perfectly! There was a good deal of joking when the scheme was announced, but listen to the report from Pensacola, Fla., where the innovation was inaugurated : —" When the test was started 12 students were unsatisfactory. After two nights, during which the radio code was sent to these students, in their sleep, only two were unsatisfactory, and these two had left the class before the experiment was finished, professing their disbelief." So tie instructors have had the last laugh, and many a man who has despaired of ever learning code may take fresh hopes. MOTOR HOUSE-REMOVER. A nine-room house, estimated to weigh '75 tons, iva.-, recently towed four city blocks along the streets of Los Angeles bv a. 5-ton , truck carrying eight tons of pig-iron ballast to give traction. Occasional stop:i were necessary to raise wires or to cut the limbs of trpes. but where there were no ruction progress was rapid. Our- continuous pull of 400 feet was made at a speed of about' two miles per hour. This rapid rate of travel was made possible by the fact that 110. block and lackle was used, the truck pulling directly 011 the timbers cairying the weight of the house. The house was first jacked up from its original location with 10-ton jacks and supported 011 12 by 12-inch beams ex ending for its full length and width. The two lowest beams were transverse—that is, at right angles to the direction in which the house was to be moved. A single four-wheel dol!cy was I put under the centre of the forward* transi vers® beam, and two dollevs were placed i under the rear beam, one near either end. This arrangement gave sufficient stability I and afforded the t-ssary flexibility in ("steering." The dol'ey wheels were : about 14 inches in diameter, and had 14-inch tyres. Tht. direct pull from the truck was transmitted to the. bouse by a lj-inch steel drilling cable. The midpoint of the cable was passed through a pintle hook on the truck, anc* , at either end the table terminated in chains that, were I passed under the lowest or transverse j timber, arid thence around the forward ends of the longitudinal timbers. The moving job was completed without any serious damage to plastering or plumbing, the actual moving time being about two hours.