1793* on maiing ice in India. 173 



pofsible ; but at the same time, 1 must beg leave to 

 observe, that, during my residence in that quarter 

 of the globe, I never saw any natural ice. 1 can- 

 not declare, that the thern>ometer has not des- 

 cended to the freezing point during the night, 

 because I never made the necefbary obsi.rvations ; but 

 the water m every other situation, excepting in the 

 pans, has not appeared to be in a freezing state. 

 The climate may probably contribute in some mea- 

 sure to facilitate the congelation of water, when pla- 

 ced ip a situation free from the heat of the earth, 

 since those nights in which the greatest quan- 

 tity of ice has been produced, were, I before obser- 

 ved, perfectly serene, the atmosphere fharp and 

 thin, with very little dew after midnight. Many 

 gentlemen now in England, have made the same re- 

 marks, in their frequent visits with me to the ice 

 pits. The spungy nature of the sugar canes, or 

 tiie stems of the Indian corn, appears well calculated 

 to give a paLage under the pans to the cold air; 

 which, acting on the exterior parts of the vef^tls, 

 may carry off by evaporation a proportion of the heat. 

 The porous subitance of thevclbeli seems equally 

 well qualified for the admifsion of the ccld air in- 

 ternally ; and their situation, being lull a foot be- 

 neath the plane of .the ground, prevents the surface 

 of the water from being ruffled by any small cur- 

 rent of air, and thereby preserves the congealed par- 

 ticles from disunion. Boiling the water is esteem- 

 ed a nectfsary preparative to thii metiiod of conge- 

 lation ; but how far this may be consonant, with 

 philosophical reasoning, I will net prr.sume to de- 

 termine. 



