NOTES AND COMMENTS

New Zealand Herald, Volume LXIX, Issue 21263, 17 August 1932, Page 8

NOTES AND COMMENTS

WIRELESS NAVIGATOR

Ocean liners may soon be equipped with a three-colour signalling apparatus similar to that used for traffic control. Experts at the Radio Research Station, Datchet, under tho Department of Scientific and Industrial Research, have produced a wire-, less navigating device which automatically records deviations from a course set on any wireless transmitting station. The device is a practical application of existing methods of wireless direction finding. Red means that the helm is to port of the true course, green to starboard, yellow that the course is truly set. The apparatus is guaranteed sensitive to three degrees, and, with more elaborate methods of detection, can be made sensitive to half a degree. The adjustable apparatus consists of two wireless receiving sets, which can be tuned in to any desired station in the normal manner. Where no station is on the exact course corrections could be made on any desired bearing. The great advantage of wireless navigation, an officer of the station explained, is that the effect of drift is entirely eliminated. Moreover, if wireless observations were taken in conjunction with magnetic bearjngs throughout a voyage, the position of the ship would be obtainable exactly without astronomical bearings. One of the attractions of the new nevigator is that, unlike a compass needle, it cannot swing. The effective indicator is a narrow beam of fast-moving electrons which are so light that they have virtually no inertia. This means that all movements of the ship are immediately shown. VITAMIN C Remarkable progress in the chemical study of the vitamins has been made during the last 12 months, says a scientific correspondent of the Manchester Guardian. Two have been isolated in a pure state and one, vitamin D, is being manufactured commercially, as any other chemical product. There is evidence now that vitamin C may soon be isolated chemically. This vitamin is the one which prevents scurvy and is present in lemon juice and other juices, conferring on them their antiscorbutic properties. In 1927 Professor Szent-Gyorgi obtained a complicated subj stance named hexuronic acid while work- } ing in the Biochemical Laboratory at Cambridge. It is found in relatively large | though absolutely small concentrations in the suprarenal glands of animals. Guineapigs fed on a basal diet which does not contain the anti-scorbutic factor die -with severe symptoms of scurvy in about 30 days, but if hexuronic acid is added to such a diet they remain healthy and gain weight consistently. The chemical constitution of hexuronic acid is being investigated by Dr. Hirst and Mr. Reynolds in Professor Haworth's laboratory at Birmingham. The acicl is a cream-coloured I crystalline powder which melts and decomposes at about 185 deg. C. Its structure is being elucidated so that the acid may be produced synthetically. Some progress in the first part of this research is reported. If hexuronic acid is indeed the anti-scorbutic vitamin, another vitamin will have been definitely isolated. Even four or five years ago the chemical isolation of any vitamin seemed almost .beyond possibility, but the prospect of having three vitamins, A, C and D, available in | bottles to-day was beyond chemists' wildest dreams.

RECORDING THE WEATHER

Drastic changes in the type of weather records obtained by the Air Ministry and overseas authorities are suggested by Sir Napier Shaw, the veteran meteorologist. He has discovered recently a number of correlations between weather happenings in all parts of the world and vast exchanges of air between the northern and southern hemispheres, and he considers that present records provide inadequate information as to the source of our air. "The essential requirement,". Sir Napier explained to a representative of the Morning Post, "is the mapping of the 'gulleys' through which air moves to and from the principal reservoir over northeastern Asia. Existing weather maps make the mistake of ignoring what is happening in the upper air. Wind records arc obtained at high altitudes from pilot balloons, but what are wanted are temperature and pressure records. Even records from the tops of poles, such as wireless transmitters, would be of value in indicating the source of the air. For the larger task I believe that small kite-bal-loons would meet the case, but the use of the wire mooring necessary would naturally have to be controlled in the interests of aircraft. It is also necessary to disentangle temperature records generally. Part of temperature effects are due to solar radiation, but if this could be subtracted we should be left with an estimate of the warmth of the prevailing air supply." Rainfall in the West of Ireland, hurricanes in the West Indies, monsoon pressure in the tropics, the strength of the trade winds, the annual displacement of the equatorial rain-belt —all tlicso happenings Sir Napier has shown to, be connected with world air exchanges. "Between July and December," he said, "the northern hemisphere receives five billion tons of air from the southern, and in the following six months the transfer is reversed. This process lags about a month behind the changes in solar radiation, and it seems reasonable, therefore, to suppose that solar radiation is responsible. Everything is rhythm and many of these rhythms are connected. The problem for the future is whether the temporary inruptions on these various rhythms can be similarly correlated and explained."