PROCEEDINGS OF GEOLOGICAL SOCIETIES. 
148 
sent day. Hence we see that the eartli is only losing heat very slowly 
now. Professor Bischoff, of Bonn, made some experiments on the rate of 
cooling of basalt, and on these Professor Helmholtz had founded a calcula- 
tion, by means of which he proved that the period which a globe of basalt 
of the size of the earth would take to cool from 2000° C. to 200° C. would 
be 350,000,000 of years. This calculation he would assume; and, as the 
extreme limits of temperature to which his reasoning would apply, he 
would take 122° F. and 77° F. The first is the temperature at which albu- 
men coagulates, and therefore no animal could live at that temperature, as 
its blood would be coagulated. As the lower limit he would take the tem- 
perature of 77° F., which had been admitted to have been the probable 
temperature of these islands at the time of deposition of the London clay, 
Professor Heer, of Zurich, had lately expressed his opinion that the tem- 
perature of Switzerland during the Miocene epoch was between 67° and 
72°, and that period was subsequent to the London clay. Assuming 
these limits, and the period above-named (350,000,000 years), as his data, 
he found that the earth, if it be supposed to be made of basalt, would 
require 1,280,000,000 years to cool through the required space. This 
reasoning was based on the well-known law of cooling of a heated body ; 
and it was obvious to every one that the second period must be much 
longer than the first one, as the hotter a body is the faster it will cool. In 
this period we have space enough for the wildest phantasies of geologists. 
Professor Haughton did not conceive that changes of climate, produced by 
alteration in the relative positions of land and water, could account for the 
facts discovered by Sir L. M'Clintock about the fossils of the Arctic re- 
gions, nor did he now believe that the axis of the earth had changed its 
position. 
2. " On the recent Discovery of Bones of the Polar Bear in Lough Gur, 
county Limerick ; with Observations on their Comparison with Bones of 
the Cave Bear, in the collection of the Earl of luniskillen." By Dr. 
Carte. — The locality whence the specimen was derived was a very famous 
one for such remains. The lake was remarkable for being supplied from 
springs, as there was no stream flowing into it ; and as there were 
caves in the district, and throughout the whole country from that to Mit- 
chelstown, it might perhaps be found that the lake was the site of an old 
flat-roofed cave, and that the animals whose bones were found there, and 
which belonged to the ordinary cave species, had lived in the district. 
They could not have been brought by drift, as the country was quite free 
from that deposit. It appears that the margin of the lake is studded with 
stone circles and other structures of antiquarian interest. The bones are 
found round an island in the lake, called Ganet Island, in shallow water. 
The whole lake is shallow, and has been much reduced in depth durmg 
the last few years by being drained by an artificial cut. The country 
people had raised several tons of bones, and sold them as manure. They 
consisted of a very heterogeneous assemblage of animals, such as deer, 
pies, horses, cows, dogs, goats, sheep, etc., witli stone celts, and fragments 
of human skulls ; the latter of various ages, some very recent. Two species 
of bears had been found fossil in Ireland— viz. the cave bear {Ursiis spe- 
Iceus) and the brown bear ( Ursm arctos), and that he believed that tiie 
subject of the present paper formed a third, viz. the Ursus mantimus. 
EoYAL School of Mines.— Dk. Peecy's Lectuees on Chemical 
Geology. -Lectuee II., December 12, 1863.— In the first lecture, the 
subject of silicon, one of the chief components of the sohd crust of the 
