82 Dr Paterson on the Temperature of 



The great diflference of depth from which the water came 

 in the different bores which I have mentioned, while the su- 

 perficial distance is so smnll, is easily to be accounted for by 

 the nimierous shifts and dislocations which are found in 

 coal strata, and more especially in the Clackmannanshire 

 field ; indeed, a whinstone dyke is to be seen traversing the 

 country between two of the bores which have been men- 

 tioned. 



We now come shortly to consider the increased tempera- 

 ture which these artesian wells are found to possess. 



When we look at the experiments which have been related 

 in a former part of this paper, we cannot but be struck with 

 the similarity of the results, as deduced from localities far dif- 

 ferent from each other ; such a resiUt cannot be accidental, 

 and cannot be explained by causes of a local nature, but must 

 be produced by some general agency, which extends OA'^er the 

 whole surface of the globe, and Avhieh is now believed by the 

 generality of geologists to be the central heat of the earth. 



It was long ago advanced by M. Arago, that artesian wells 

 were the only sure way of arriving at any correct data by 

 which to judge of the increase of temperature as we descend 

 in the crust of the earth. The temperature of mines had 

 previously been much attended to, but the results were found 

 so various, and the sources of fallacy so numerous, that no 

 correct data could be based upon them Avith any confidence. 

 In reviewing our experiments, it will be obvious that they 

 bear upon two very important topics connected with this sub- 

 ject, and these are, first, the rate of increase as we descend, 

 and 2f%, the regular ratio which it bears. 



This latter point is distinctly shewn by observing the tem- 

 perature of artesian wells of small depth, and comparing them 

 with those of great depth. Indeed, so much can this be de- 

 pended on (at least in the districts we have examined), that 

 on several occasions when individuals totally miacquainted 

 with the subject have been told the mean of the district, 

 and the usual rate of increase which had been found in other 

 springs in that neighbom-hood, as well as the depth of the 

 spring we were about to examine, they have told the tem- 

 perature very nearly. 



