IN THE 16-HOUR DAYS.

Stratford Evening Post, Volume XXXV, Issue 96, 30 April 1913, Page 3

IN THE 16-HOUR DAYS.

THE MOON’S EFFECT. -i ’•* People who do not find a day of 21 hours long enough would have had far more reason to complain had they lived about 4G millions of years ago. Then the day, rs Professor H. H. Turtle* pointed out in a lecture at the Royal Institution recently on “The Movement of the Stars’ —was only 16 hours, though there we’re 29 days in the month.

Some ten million years before that the day,was ten hours in length, and going back still further to one hour. That was when the earth and the moon were very close together—when they had only recently parted company, in fact, and had started on their career as separate bodies. The principle ap plied to a. very large class of bodies in the sidereal sysfem—the double stars, They knew two stars in the sky so close together that it had never been possible to separate one from another, even through the best telescopes, though it was known that one of them was very considerably brighter than the other, and it was supposed that one was describing an orbit round the other. At the end of the scale there were some stars that had not completed their orbit in the century since they wore described by Herschcll. Some of them might occupy two or' three hundred years, and there were even instances in which the orbit would occupy thousands of years. The cause of the changes in the length of our day, said Professor Turner, was the effect of the tides on the earth’s rotation. Hie moon raised Invo tides-r-on one side liecause she pulled away the water from the earth, and on the other because she pulled away tho earth from the water.