ACTION Of HEAT MODIFIED, &rC. ] }3 



The water ram of M. Turquct, taken by the medium rate of The two en- 

 estimation (namely, according to Desaguliers*) is equal to one-al-g^o,!'^ vJl-y'^ 

 third part of a man, or one-fifteenth part of an horse. s'^-'ll scale ^ 



The engine at the author's houseworks at the rate of one- a!id<jiie-ciVi,i.h 

 eighth of a man's power ; so that a man woulil require three ^^'-^ "'*'i- 

 hours to raise as much water as the engine raises in 24 hoiirs. 



We must therefore consider the^e eiiGjines as models or small '^-"i>"S«^'" «^x-liibi- 

 works capable ot being multiplied : but we have not yet any 

 practical results on a large scale. 



The water ram appears to be a very ingenious contrivance, 

 but it is by no means any new principle or extraordinary effect 

 in hydravilics, as some \yiiters have pretended. 



IV. 



Account of a Series of Experiments, shcxviyig the Effects of 

 Compression in modifijiitg the Effects of Heat. By Sir 

 James Hall, Bart. F.R.S. Edinburgh. 



(Continued from page 22. J 



Sect. vi. — Experiments made in Platina, — xvifh Spar, — with 

 Shells, — and with Carbonate of Lime of undoubted puriti/. 



Si 



'INCE I had the honour of laying before this Society a Suspicion that 

 short sketch of the foregoing experiments, on the 30th o/thecarbona^'s 

 August last (1804), many chemists and mineralogists of emi- arose from im- 

 nence have favoured me with some observations on the sub- ^" ' 

 ject, and have suggested doubts which I am anxious to remove. 

 It has been suggested, that the fusibility of the carbonates 

 itiay have been the consequence of a mixture of other sub- 

 stances, either originally existing in the natural carbonate, 

 ©r added to it by the contact of the porcelain tube. 



With regard to the first of these surmises, I beg leave to If sothiswoulii 

 observe, that, granting this cause of fusion to have been the fnferences. 

 real one, a material point, perhaps all that is strictly necessary 



* On men and horse powers, as computed by eagineers. See 

 J*hilos. Journal, ix, pp. ^15,— -217. 



Vol. XrV.— June, 180^. Q, in 



