480 Modes of rendering Salt Water fr eft. [Book VII. 



of the vcfTel. Upon thefe principles, a mode of ob- 

 taining a fupply of frefti water at fea was recommended 

 fome years ago to the Admiralty, by Dr. Irving. It 

 confifted in only adapting a tin tube of fuitable dimen- 

 fions to the lid of the common mip's kettle, and con* 

 denfing the iteam in a hoglhead which ferved as a 

 receiver. By this mode a fupply of twenty-five gal- 

 lons of frelli water per hour might be obtained from 

 the kettle of one of our fhips of war. I have not nn- 

 derflood, however, that the plan has been as yet intro- 

 duced into general practice. 



