APPENDIX. 

 " Sea- water, when boiled down to a ftrong brine, admits 

 " with difficulty the feparation of frefh water from it; the 

 " diftillation becoming flower as the ftrength of the brine 

 " increafes, fo that a greater quantity of fuel is confumed 

 *' in procuring a fmaller portion of water, and this like- 

 " wife of a bad quality. From this efTential circumQance 

 " arifes the neceffity of letting out the brine by the cock 

 " of the boiler, when the diftillation is advanced to a 

 " certain degree ; and of adding more fea-water to con- 

 " tinue the procefs if required. 



" The defeds of the feveral fchemes formerly propofed for 

 *' rendering fea-water frefh being pointed out, the general 

 " principles of diftillation explained, and the component 

 " parts of fea-water analytically examined ; the advan- 

 *' tages of the method invented by Dodor Irving remain 

 " to be flatedj which may be reduced to the following: 

 '* I. The abolin:iing all ftills, fti 11 heads, worm pipes, 

 " and their tubs, which occupy fo much fpace as to 

 " render them totally Incompatible with the neceiTary 

 " bufmefs of the fhip; and ufing in the room of thefe, 

 " the fhip's kettle or boiler, to the top whereof may oc- 

 *' cafionally be applied a fimple tube, which can be eaflly 

 " made on board a vcffel at fea, of iron plate, Hove 

 " funnel, or tin fheet; fo that no fltuation can prevent a 

 " fhip from being completely fupplied with the means of 

 " di Hilling fea-water. 



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