THE CAUSES OF AN ICE AGE
Reading edition
We know that our Earth has passed through several ice ages, in the past, and various astronomical theories have been advanced in order to explain this fact. Perhaps the most ingenious of these is that advanced by Sir Robert Ball (see his “The Cause of An Ice Age”). Very briefly, it is that the eccentricity of the earth’s orbit and the tilting of the polar axis causes an ice age, or the reverse. If the northern axis is tilted towards the sun, when nearest to it (so to say), then the northern hemisphere will enjoy a genial climate, and if the southern axis be thus tilted, the reverse conditions will prevail. This, and various other theories have, however, been discussed by Finger in his book on “The Ice Age,” in the present series, No. 327.