348 Summary Review of the late luvesliga/ions 



Dr. Forbes ; and also, to complete the subject, as far as it has 

 been investigated in this country, we shall subjoin an abstract 

 of a paper by Mr. Bald on the temperatures of some of our 

 northern collieries*. We shall not enter into the theoretical 

 part of the subject any further than may be necessary to ex- 

 plain some of the contending relations ; but it may be well to 

 remark, in this place, that Mr. Fox and Dr. Forbes are of 

 opinion, that their observations prove the existence of a high 

 temperature in the interior of the earth, while Mr. Moyle 

 refers the augmentation of temperatiu'e in the mines entirely 

 to causes of a local and accidental nature. With respect to 

 the general question, we believe that MM. Laplace, Gay- 

 Lussac, and Arago, and the President of the Royal Society, 

 agree in thinking that the various observations which have 

 been made on the temperatures of mines do prove the present 

 existence of a high temperature in the interior of the globe ; 

 while Professor Leslie and other eminent men of science are 

 of the contrary opinion. 



I. The following Table is a copy of that which constitutes 

 the most important part of Mr. Fox's first communication on 

 this subject to the Geological Society of Cornwall (Trans, vol. ii. 

 p. 14) ; being slightly modified in its arrangement, for the pur- 

 pose of accommodating it to our pages. It exhibits at one view 

 the results which have been obtained in the mines of Huel 

 Abraham, Dolcoath, Cook's Kitchen, Tincroft, and in the 

 United Mines ; distinguishing the tem}5erature of the air (a) 

 from that of the water (w), and stating the respective depth of 

 each mine, which corresponds with the level of the sea, as 

 given in R. Thomas's Survey of the principal minuig district 

 of the county. 



" Without entering into speculation on the exciting cause, 

 or the extent of the internal heat," Mr. Fox observes, " it is 

 probable that the ascent of warm vapour may produce the 

 high temperature noticed in mines ; and that its effect is more 

 or less considerable, in proportion to the facility with which it 

 finds a passage upwards. This is rather corroborated by the 

 fact, that water flowing from large metallic veins is generally 

 the most remarkable for warmth." 



* An account of the principal observations on this subject that Tiave 

 been made on the continent, has been given by M. Daubuisson, in his 

 Traite de Geognosie, torn. i. p. 444 et seq. His Obsei*vations upon Subter- 

 raneous Heat, made in the Mines of Britanny, will be found in the Phil. 

 Mag. vol. xxxiii. p. 320.' 



