40 NEW THEORY OF THE ORIGIN OF THE EARTH. 



for by the new hypothesis in this way : The oxygen and nitrogen 

 of the atmosphere are transparent to "dark heat." while carbon 

 dioxide intercepts and stores it. So the temperature of the 

 atmosphere is largely due to how much carbon dioxide and water 

 vapor are in the air. The carbon dioxide forms but one three- 

 thousandth part of the atmosphere. But so exceeding potent is 

 it that a very small variation makes a vast difference in climate. 

 The amount of water vapor in the atmosphere intensities the 

 effect produced by the carbon dioxide. So the latter may be 

 regarded as the climate maker. 



It is shown conclusively by Prof. Fairchild that carbon dioxide 

 comes from the earth's interior, instead of from organic sources, 

 and it is assumed that therateof sup[)ly from volcanoes, springs 

 and other known sources is fairly uniform. But this gas is 

 withdrawn from the air by rock decay and l\v vegetation, and 

 is stored in rock strata and the sea. Periods of the earth's 

 history when great expanses of land were elevated from the ocean 

 and when extensive limestone formations occurred have been 

 followed by cold climate, as these conditions absorbed carbon 

 dioxide largely from the air. Tn this w^ay the glacial age is 

 accounted for — the age when an immense glacier slowly moved 

 down the valley of the Miramichi, depositing boulders and scor- 

 ing rocks in its progress. We have, in our museum, a specimen 

 of rock from Bartibog Island that bears the footprints of this 

 glacier. But subsidence of laud and large increase in water area 

 tend to bring about an excess of earbon dioxide in the attnos- 

 phere. Any enrichment of the air in this gas is like a blanket 

 thrown around the earth, giving the atmosphere power to retain 

 sun heat, and produces warmer and more uniform climate with 

 greater moisture. Lessening the amount of carbon dioxide 

 makes the air more transparent to reflected heat. The l)lanket is 

 thinner, the temiteralure falls, the moisture decreases, and zones 

 of climate are formed because the earth becomes more dependent 

 on the direct heat from the sun which varies with the slant of 

 its rays. 



The ocean is an equalizer of climate, not so much because of 

 th^ water vapor it sends up into the air, but because it is a 



