THE MOON

Evening Post, Volume LXXXVIII, Issue 74, 24 September 1914, Page 4

THE MOON

LECTURE BY SCIENTIFIC VISITOR. The Moon ! How many laymen give more than a passing thought to it? How Biauy consider how useful it has been in >ie evolving of nuineioiis scientific theories? Yet tho study of the moon has proved the lifetime woik of many an abtiologur, a-.ul now observations are taken regularly at Greenwich and other famous observatories. The moon is a fascinating subject oven for a layman. Under the auspices of the Wellington Philosophical Society, Professor Ernest W . brown, of Yule Univeuity, delivered at Victoria College last night an interesting, though technical, lecture on the moon. There was an attendance of about lorty people. He did not speak about the volcanoes, but of the moon's .motion, and of the motion of the earth, sun, and other objects of the solar system. Some of his friends, he said, had j stated that it was impossible to lecture on such it subject to a l.iy audience, but he had done so twice previously since leaving England— once on the boat, when some of the audieme kept awako, and again in Sydney, when, lie thought, only a tew went to sleep. (Laughter.-) lie gave the results which had been oLtained during the last tLv or eight months as to the moon's motion. This took the 'form of an ellipse, but not a pei feet ellipse. It would be perfect iE it had to contend with the earth only. but it was affected by the sun, and possibly by the various planetd. The enormous size of the sun attracted the moon and altered its orbit considerably, and the shape or eccentricity was affected. The moon was not of much practical use these days, and of this the lecturer wa3_gJad, because astiologers weio able to give more time to deeper study, which would not, have to be hurried. The moon was not used now as an aid to navigation. It was up to 20 or 30 years ago when it was used "to obtain Greenwich lime, but chronometers had been brought >to such perfection that the moon had been discarded. Many of the latest nautical almanacs had even omitted calculations for obtaining lunar distances. Then there was the advance made by wireless telegraphy. The moon had been used to- prove many physical laws, but particularly the law of gravitation. It had proved that law to be correct to the extent of one part in every four hundred million. That was an extremely accurate calculation. It was the same as if the world's circumference was measured by a tape measure and found to be one yard out. Careful observations of the moon continued to bo tak«i at Greenwich, and there were now comprehensive records totalling about 20,000 — a wonderful storehouse of astionomical facts collected during tho past ISO years. But there were still some problems to be solved. They had still to find tho cause of the moon's deviations. The moon was affected by some power or agent as yet undiscovered. Maybe the sun-spot period had something to do with this, 'but nobody could say as yet. The lecturer was accorded a hearty vote of thanks.