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Palaeozoic ages than now. 2nd. That the ocean currents are the 
chief agents employed in the distribution of heat over the 
globe. 3rd. That while, during portions of the Glacial period, 
England and much lower latitudes had an Arctic condition 
of climate, yet, during other portions termed “ Interglacial,” 
a warm condition extended to Greenland and the Arctic 
regions generally, which then were not only free from ice, but 
covered with a rich and luxurious vegetation. 4th. That this 
condition of things is accounted for on the theory of a great 
increase in the eccentricity of the earth’s orbit, which brings 
into operation a series of physical agencies, the direct tendency 
of which is to lead to a glacial condition of things on the 
hemisphere whose winters occur in aphelion, and a warm and 
equable condition of climate (interglacial) on the opposite 
hemisphere, whose winters, of course, occur in perihelion. The 
precession of the equinoxes reverses the condition of each hemi- 
sphere alternately, about every 10,000 years as long as the 
eccentricity continues at a high value, which eccentricity about 
850.000 years ago Mr. Croll computes at 0‘0747.* 
71. Hence we may reasonably conclude that what has hitherto 
been a somewhat perplexing knot for our geologists, naturalists, 
and botanists to untie, may now be accounted for by the 
hypothesis of Mr. Croll as given above. All these things, 
and various other matters, which have been so fully, ably, and 
temperately discussed by Mr. Croll in his work on Climate 
and Time, may serve to explain the problem of a past flora 
and fauna existing in latitudes where at present they are 
unknown. 
72. The older and more perfect science of Astronomy con- 
firms the view derived from Geology, so far as it bears upon 
the meaning of the antiquity of the heavens and earth, which 
may have been created myriads of millions of years just as 
readily as thousands of years ago, so far as the words of Scrip- 
ture are concerned. But that it could not mean merely 
6.000 years ago, the limit of man’s antiquity on earth accord- 
* “ How totally different,” says Mr. Croll, “ must have been the condition 
of the earth’s climate at that period, from what it is at present ! Taking the 
mean distance of the sun to he 91,400,000 miles, his present distance at mid- 
winter is 89,864,480 miles : but at the period in question, when the winter 
solstice was in perihelion, his distance at mid-winter would be no less than 
98,224,289 miles. But this is not all ; our winters are at present shorter 
than our summers by 7'8 days, but at that period they would be longer 
than the summers by 34’ 7 days. At present the difference between the 
perihelion and aphelion distance of the sun amounts lo only 3,069,580 miles, 
but at the period under consideration it would amount to no less than 
1 3,648,579 miles ! ” ( Climate, and Time, p. 359.) 
