WATER HEATED TN A BOrtER OF STONE. 159 



VL 



Accotmt of a Fa6t refpe^ing Water heated in a Boiler of Stone ; 

 with Obfervalions. By Mr, J. C. Hornblowek. 



To Mr. NICHOLSON. 



Dear Sir, 



JL hough it muft be admitted by every one who has at- Fluids not 



fended to the critique contained in your note on the experi- ^"'^ly "»"- 



■^ conductors. 



ments of Count Rumford, in your firfl volume * of the Philo- 



fophical Journal, concerning the non-condu6ling power of 



fluids with regard to heat, that it is an erroneous conclufion, 



and which feveral experiments, particularly that of Mr. 



Murray, hav-e fince confirmed ; yet I cannot be quiet without 



informing the gentlemen who have fo conftanlly oppofed the 



Count's dodrine, of a circumftance which accident brought Incident. 



forth on a very large fcale, about forty years ago, in the county 



of Cornwall. 



It had long beena defideratum in the mining interefl in Attempt to re- 

 that county, to reduce the confumption of fuel in draining the ^^^ ^^.J *^""* . 

 mines by the means of fleam engines, and every expedient in working 

 that carried any tolerable face of probability was brought to a ^^^"™ engines. 

 trial. 



Among the reft it was fuggefted, that as, in the feveral Tiial to work 

 operations of fmelting the produce of the mines, much heatj^^^^^ "^ meting 

 muft be carried off, from the intenfe fires of their furnaces, 

 which might be employed to fome purpofes requiring but a 

 fubordinate temperature ; a refolution was formed by a com- 

 pany of gentlemen, with Mr. John Wefton at the head of it 

 (to whom mining was an ungovernable hobby-horfe), to ere6l 

 an engine on a copper mine in the parifh of Camborne, and to 

 put up a fet of furnaces fo attached to the engine that they 

 might avail Ihemfelves of this fuperabundant heat to raife the 

 fleam. 



To effed this they had their engine-boiler made of mafonry, a ftone boiler 

 of what is called in Cornwall moor-llone, well wrought and put cenneded with 



• .... 1 1- 1 ■ , I . r r ■ water-iime, &c. 



together with Aberthaw lime, which has the property oi letting heated by cop- 

 per tubes. 

 * I. Page 291, Quarto Series, 



like 



