V 



/ 



3SS 



M 



PAPERS. 



i^ 



feet from the nozle of the pump, a man can raife In an 

 hour, with common working, about thirty-eight hog- 

 Iheads, which far exceeds the work performed by the 

 wheel; but this calculation is made on pumps of the com- 

 mon fize, I would therefore propofe that all veffels fhould 

 carry larger pumps, the advantage of which will appear 

 from the following table: 



A 4 inch bore will difcharge per hour, falling at the rate 



s^ 



of five knots, - 



5 inch, 



6 ditto, 



7 ditto, 



8 ditto, 



9 hogflicads 



14 and an half. 

 20 and l-ihs. 

 28 and 4 th. 



37 hoglheads. 



Hence 



difcharge with the wheel nearly the fame quantity that a 

 man commonly ralfes. If both pumps be fet to work by 

 the crank, double the quantity, or 74 hogflieads will be 

 difcharged; but if a cog wheel, of about three feet ten in- 

 ches, with 51 cogs, be fixed on the end of the fliaft or 

 axis, and the crank be paffed through a trundle or lanthorn 

 wheel, of about two feet diameter, with thirteen rounds, 

 to work with the axis parallel to the deck, and fixed to the 

 pumps, in the manner ufed by brewers and diftillcrs, the 



crank will make about four turns to one revolution of the 



great wheel, and of courfe deliver 296 hogfheads per hour; 

 yet as the refiftance made by the pumps will, in fome mea- 

 sure, impede the motions of the wheel, it will not turn at 

 the rate of 730 times in an hour, for which fuppofe a de- 

 <]udion of one third, which is certainly a great allowance, 

 the quantity then difcharged per hour is about 200 ho 

 fheads, which is more than equal to the conftant work of 

 five men; thus. if a veffel failing at the rate of 5 knots, de- 

 livers 200 hogflieads per hour, equal to five men's work. 



equal to 6 ditto, 

 equal to 7 ditto, 

 equal to S men's work. 



I am 



^ 



rr 



a 



6 knots is 



7 knots 



S knots 



240 



280 

 320 



