THE EARTH'S AGE.

Dominion, Volume 4, Issue 972, 12 November 1910, Page 10

THE EARTH'S AGE.

SCIENTISTS' CONFLICTING VIEWS. Geologists and physicists have differed for many years in their estimates of the geological ago of tho earth'. As a rule, geologists have placed their esat 300,000,000 years, ,whilo the physicists deduced, principally from thermo-dynamic conditions, tlio comparatively short ago. of 20,000,000 or 30,000,000 years... Professor Frank Wigglesworth Clarke qnd Mr. George F. Becker, of the United States Geological Survey are the latest scientists to estimate the age of the earth. They say its age is "not over 70,000,001) nor bolow 55,000,000 years." This estimate has received official sanction through its publication by the Smithsonian Institution. ' Professor Clarke presents- his deductions from a chemical standpoint, and reviews all the available data collected from various parts of tho world. His thesis 011 the subject is entitled "A Preliminary Study of Chemical Denudation." Mr. Becker writes on the subject more from the philosopher's point of view, and the title of his paper is "The Age of the Earth."

Tho reason why scientific men rarely have agreed as t-o the timo our planet has been in existence is because each man has drawn his deductions from facts obtained by research work in his own particular scientific branch of knowr ledgp. The more recent men have given their opinion of t-lie ago of tho earth as follows Lord KeH'in, ill 1862, 20,000,000 to 400,000,000 years, with a probablo 98,000,000 years. Clarence King and Carl Barus, in 1893, 24,000,000 years. Lord Kelvin in 1597 revised his figures to 20,000,000 to 40,000,000 years. Do Lapperant, ip 1890, 67,000,000 to 90,000,000 years. Charles D. Walcott, secretary of the Smithsonian Institution, in 1893, maximum ago, 70,000,000 years.

J. Joly, in 1899, age of the ocean, 5Q,000,000 to 90,000,000 years. AV. J. Sollas, in 1909, age of the ocean, 80,000,000 to 150,000,000 years. Sopie time ago Strutt deduced, from tlie ■ proportion of helium found in thorium ores, a lower limit of 2-10,000,00(J years for the age of the earth.. The same physicist has recontly attempted to determino by direct experiment tho rato at which helium is generated in thorianite and pitchblende. Ho found that the quantity of helium produced by 400 grams of thqrianite in seven weeks was certainly less than 2x16-8 cuhic centimetres. From this it follows that one gram of thormiito generates less than 3.7x10-61 cubic centimetres of helium per year. Hence, at least 240,000,000 . years must bo allowed for the accumulation of the nine cubic centimetres of helium which are actually found in each gram of freshly mined tliorianitc. And this would leave the question of the earth's ace as much of a mystery as ever.