AT CHATRA IN RAMGUR. 313 



in a tub, that, from the nature of its porous fub- 

 ftance, in a great degree rather retains than lets the 

 heats pafs away, it foon accumulates in it, and becomes 

 very hot ; and, though renewed pretty often, never 

 anfwers the purpofe of cooling the vapour in the worm 

 fo expeditioufly and effectually, as is done by their more 

 fimple and lefs expenfive apparatus. In this country, 

 more efpecially, where labour and earthen-wares are fo 

 cheap, for as many rupees, and lefs, twenty furnaces, 

 with ftills, and every thing belonging to them, inde- 

 pendent of the copper-pots, might very well be erected, 

 that would yield above a hundred gallons of fpirits a 

 day; allowing each (till to be worked only twice. So 

 very cheap, indeed, is arrack here, to the great comfort 

 of my miners, and of many thoughtlefs people befide, 

 that for one fingle peyfa (not two farthings fterling) 

 they can get a whole cutciia-feer of it in the bazar, or 

 above a full EngUJJi pint, and enough to make them 

 completely intoxicated; objects often painful to be 

 feen. 



Of the fuperior excellence of metal in giving out 

 heat from itfelf, and from vapour contained in it, we 

 have a very clear proof in what is daily performed on 

 the cylinder of the fteam engine : for cold water being 

 thrown on it when loaded, the contained vapour is con- 

 stantly condenfed ; whence, on a vacuum being thus 

 formed, and the weight of the atmofpbere acting on the 

 furface of the pifton attached to the arm of the balance, 

 it is made to defcend, and to raife the other arm that is 

 fixed to the pump ; while this being fomewhat heavier, 

 immediately finks again, which carries up the pifton, 

 while the cylinder is again filled ; and thus by alter- 

 nately cooling and filling it, is the machine kept in 

 motion; the power exerted in raifing the pump-arm 

 being always in proportion to the diameter of the cylin- 

 der, or to the furface of the pifton, which is exactly 

 fitted to it, and on which the preflure acts. 



Vol. I. Z The 



