THE AGE OF OUR PLANET.

Colonist, Volume LVI, Issue 13486, 4 June 1914, Page 7

THE AGE OF OUR PLANET.

The age of the earth is a favourite problem among scientists, possible because anyone can calculate it as he pleases, and no one" can prove him wrong. M. Dudki uses as his basis the thickness of the sedimentary rocks compared to the rate of deposit of modern streams. His' , calculations show a minimum age of 200,000,000 years. This is, of course, subject to the doubt as to whether the rate of, denudation of the earth's surface re-' mains constant. Prof essor - Joly takes as the base of his calculation the saltness of the ocean. He-assumes that the ocean was entirely fresh at first, and that all the salt has been brought to it by streams, washed out of the earth by rain. All one has to know is the amount of salt in the ocean and the rate at which the rivers supply it. If this rate has remained the same through all the earth's history, Professor Joly says the age would be 95,000.000 years. But Romer, with the same material to guess by,, says it is 160,000,000. Still another way to calculate it is new. It is based on the disintegration of radio-active minerals; the best guess by this system is anywhere from 710,000,000 to 1,025,000,000 years.