VOYAGE TO MADAGASCAR. I5I 



That I may more fully convince the 

 planter of. the mility of fteam-engines, 

 I fhall fhew, that, even at Paris, they fave 

 a great deal of expenee in the moft commoa 

 labours. When a load of coals, weighing 

 tweaty-feven hundred weighty cofts in that 

 capital fifty-four livres, M, ^rrier, of the 

 Academy of Sciences, whofe calculations 

 ferve me as a bafis, values at no more than 

 fix fous the quantity neceflary to produce 

 a moving force equivalent to that of a 

 horfe labouring eight hours, and making a 

 conftant effort of about feventy-five pounds. 

 As the ftrength of a man is only the fe- 

 venth part of that of a horfe, it follows, 

 that his labour for a day may be fupplied 

 by a confunaptien of coals to the value of 

 ten deniers. In the greater part of our co- 

 lonies, wood, and other fuel, fuch as trqfht 

 are abfolutely of no value. Why then do 

 the planters negle£t to employ a machine 

 L 4 •f 



