1866.] On the Antiquity of the Volcanos of Auvergne. 201 
that required, according to the computation of mathematicians, for _ 
the cooling down of the earth from its original vaporous or incandes- 
cent condition, to a temperature such as admitted of the existence 
of life, as the distance between ourselves and the sun does to that 
which divides this luminary from the nearest of the fixed stars. 
Thus, let us call the And, calling the distance from the 
circumference of the globe, present time to the birth of Adam, 
Then the distance from The distance from the same to the 
the earth to the moon will commencement of the post-pleiocene 
be epoch would be 
10. 10. 
Distance from the earth Distance in time from the com- 
to the sun, mencement of the post-pleiocene epoch 
400. to that at which organic life began 
would be 
400. 
Distance from the sun to Distance in time from the com- 
the nearest of the fixed mencement of organic life to the period 
stars (viz. 61 Cygni) will when the earth was first created, would 
) be 
160,000. 160,000. 
I have been led to these general remarks by the subject which has 
been proposed for the present communication, in which it will be 
attempted to show that the phenomena presented by the extinct 
volcanos of Auvergne tend in a very marked manner to cor- 
roborate the inferences which, on other grounds, I have deduced 
with regard to the long space of time that must have been consumed 
even by that one stage in the earth’s history which connects itself 
most nearly with the present, not to speak of that almost intermin- 
able series of antecedent deposits which contribute to make up the 
entire crust of the globe. 
In order to render this subject more intelligible, it will be neces- 
sary for me to enter into some details, which may appear to some 
rather egotistical, as they will involve an account of my earliest visit 
to Auvergne, which took place in 1819, before any other British 
geologist, since the peace with France, had explored the district. 
T had come at that time fresh from the lecture-room of Professor 
Jameson, of Edinburgh, who was regarded a great authority in 
Geology, partly from the accurate knowledge he possessed of the 
characteristics of rocks and minerals, and partly as being one of the 
very few of our countrymen who had studied under Werner, the great 
Freyburg Professor, whose opinions respecting the structure and 
formation of the globe gave the law at that time to all who had 
studied under him. 
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