Rensselaer Semi-Weekly Republican, Volume 22, Number 76, Rensselaer, Jasper County, 11 June 1901 — AGE OF THE EARTH. [ARTICLE]

AGE OF THE EARTH.

Scientista Place Habitable Time at 20,000,000 Years. Figures, it must appear to many thinkers, lose their substantial meaning after they pass the million stage; the fact that we can say seven or ten or a hundred million does not mean that we/an grasp what these millions have power to effect or that we can follow them out into the beginningless tract of time and space. However, to such people as may think they are able to follow battalions of figures it may be of Interest to give the latest opinions on the work of the geological ages. Lord Kelvin estimates the age of the earth, since it was sufficiently cooled to become the abode of plants and animals, to be about 20,000,000 years, within limits of error perhaps ranging between 15,000,000 and’ 30,600,000 years. This estimate, nearly agreeing with another by Clarence King from similar physical data, has generally been regarded by geologists, says Warren Upham In the American Geologist, as too short for the processes of sedimentation and erosion, and for the evolution of floras and faunas, of which the earth’s strata bear record. More probably, as ratios and computations by Dana, Walcott and other geologists somewhat harmoniously indicate, the duration of time since the beginning of life on earth has been three to five times longer than Kelvin’s estimate, or from 60,000,000 to 100,000,000 years. The larger figures Imply from the dawn of life to the development of the Cambrian and Silurian faunas probably 50,000,000 years; thence to the efid of Paleozoic time perhaps 30,000,000 years; onward through Mesozoic time about 15,000,000 years, and through the Tertiary era about 5,000,000 years. The comparatively very short Quaternary era, having In its organic revolution, as shown by the marine mollusca, no higher ratio to tertiary time than 1.50, may therefore have occupied only about 100,000 years.—American Catholic Quarterly Review.