SOME SCIENTIFIC AIDS TO PROGRESS

Manawatu Times, Volume 61, Issue 194, 18 August 1936, Page 10

SOME SCIENTIFIC AIDS TO PROGRESS

rj'HE NATIONAL Physical Laboratory, which has just celebrated its thirty-sixth birthday, has seen one scientific revolution alter another since it began its existence at Jiushey House in the last days of Queen Victoria’s reign. Then, there were no aircraft, hardly any motors, neither wireless nor long-distance telephone; the grid did not exist and—blessed age!— the problem of noise did not matter. To-day the laboratory covers more than twenty acres, and employs six or seven hundred men in the great experimental shops at Teddington. Some of the work, of course, is practically routine —the testing of clinical thermometers, for example, and the taximeters on cabs. (Actually they cairy out this latter test at a small branch at Lambeth, and some passengers may wish that they tested the chassis as well as the meter.) The testing of standard weights and measures is more complicated, Ihe yard and the pound avoirdupois are familiar friends, but the electrical age has introduced a new series of terms—ohms volts, and amperes, which in a liiiguistie- sense are to-day more than technical but on the whole rather less than vernacular English. /Then, also,,there is the wave-length which is coming more and more to the front as a convenient (because invariable) measure unafFected by climate or temperature or distance, or scientific purposes at least this seems destined

slots, and the reduction of resistance by good streamlining, and these results should have a useful elfect on aircraft design. Even more important, perhaps, are the experiments that have recently been made as to the effect of surface roughness in reducing speed. Roughness on the wings of an aeroplane must obviously increase wind resistance, and it is now known that a roughness corresponding to grains four-thousandths of an inch in size can produce an increase of some 30 per cent, in the resistance of the wing of a modern aeroplane travelling at, say, 200 miles an hour. The graphs on which these icsults are demonstrated are both scientifically and practically of the first importance. Finally, there is that matter of noise. The laboratory is not concerned with nerves, and it is emphatically not a psychological institute where insomnia can be treated by hypnotism or suggestion. But there aro two completely insulated rooms here, with movable floors based on rubber, that practically exclude sound. But for the fact that they also exclude light and fresh air, there would be something to be said for converting this section of the laboratory into flats for harassed Cockneys. The scope of the National Physical Laboratory’s activities is still growing, but the work of its electrical and other sections is of too technical a nature to be described without illustrative graphs and diagrams.

TESTING TANK FOR SHIPS

to become, within a few years, the standard international measure. These matters are somewhat abstract and recondite, and the National Physical Laboratory is probably better known to the public for its work on ships. Everybody has heard of the tank at Teddington —in actual fact there aro two tanks—in which models of ships (constructed of paraffin-wax) are tested for the resistance of water to any particular typo of hull, with wave-effects complete at one cud of the tank. It sounds like the ideal schoolboys’ ideal hobby, but the work in this particular building has had a very definite effect on ship-design during the past twenty years, and more still on fuel consumption. To como to actual figures. In 1934 there were sixty 6hip designs tested at the laboratory, in 1935 there were seventy-three. This involved the making of 160 ship models, and in sixtyfour of these the tank suggested effective improvements. In thirteen the improvements represented an economy of more than 10 per cent, in fuel con-

36 Years’ Laboratory Work

sumption, and in four cases an economy of 20 per cent. Research work on small craft, which was begun in 193-1, has already resulted in a reduction of 30 per cent, in the power required for heavy steamers. It Seems probable that there Is room for further research on the design of paddle-steamers —a type of craft which has rather fallen into the background and made little if any progress for many years. The aerodynamics department is less spectacular, simply because most of the work on model aeroplanes is done in a tunnel, not in a tank. Research on air How is progressing steadily, and an ingenious method has now been deviled which photographs the shadows of small 6pots of hot air moving with the current. The hot air spots are produced at suitable places by tiny electric sparks, and by the use of slow-motion cinematograph the movements, though too rapid to be followed by the eye, are slowed down to a speed at which every detail of the motion can be seen. The films obtained show very clearly the nature of such phenomena as the stalling of wings, the effect of wing