MECHANICS. 115 



The value of H is deduced from the ascent of the 

 Peak of Teneriffe. BORDA, accompanied by eight 

 men, on foot, ascended in the first day, or in (7h 

 45m), to the height of 2923 metres, or 9593 feet 

 This was at the rate of 1225 feet in an hour. Had 

 each of the men carried a load equal to the fourth 

 part of his weight, they would only have ascended 

 at the rate of 857 feet an hour. 



AVhen 1 - = 0, or Z=2o>, the height h = 0. 



With a load equal to twice a man's weight, he 

 could not ascend. 



184. The strength of a man being supposed to 

 follow the law now laid down, its greatest effect 

 in raising a weight, will be when the weight of 

 the man is to that of his load as 1 to 1 + V 3, 

 or nearly as 4 to 3. 



Because h = - l h= 



w 



now / /&, or the weight multiplied into the height to 

 which it is raised, is the measure of the effect, 

 or of the work done, which, therefore, will be a 

 maximum when the last formula is so, that is 

 when / = ;(! -f V 3). 



H w (1 - 5 



T/. . 1 2 2o>x 



It in the equation /* = -. , we suppose 



