163 



On the mode of raising Water in India. [April 



nute, for 8 or 10 hours a day, by walking' backwards and forwards 

 on a lever." 



15. "A young man weighing 135 lbs. and carrying 30 lbs. 

 raised 9J cubic feet of water = 578-i-ybs. avoirdupois, 11 J feet high 

 for 10 hours a day without being fatigued. 



16. Before 1 proceed to remark upon the data thus laid down, I 

 must insert a few experiments on the strength of Bullocks with which 

 I have been favoured. They were ma<le a few years ago at Serin- 

 gapatam, by a gentleman who had given much attention to the sub- 

 ject and there is every reason therefore to beheve that they have been 

 accurately made and may be depended on, while they are the more 

 valuable because they are sound and of direct practical utility. The 

 cattle employed were of 3 different sizes; — large, inferior and small. 

 The large cattle weighed about 850 lbs. each, the inferior about 700 

 lbs. each, the small about 500 lbs. each. They drew up out of a 

 dry well weights by means of a rope and pulley ; they were yoked in 

 pairs as usual ; but had a 561b. weight hung to the yoke to assist 

 traction. 



The large size pair drew up with tolerable ease 430 lbs. with difficulty 486 lbs. 

 The inferior do. do. do. 346 do. 402 



The small do. do. do. 274 do. 386 



17. The dynamical unit of writers on mechanics varies. I shall 

 adopt that of Mr. Watts in estimating the power of his steam en- 

 gines, v^hich is equivalent, to 33,000 lbs. raised one foot high per 

 minute, or to a force of traction of 150 lbs. moving at the rate of 

 2 1 miles an hour for a one horse power. Let also 6 men be consi- 

 dered equal to one horse, and the dynamical unit for one man will 

 be 5,500 lbs. raised one foot high in one minute, which is indeed a 

 very high estimate, to be attained in practice only by the physical 

 weight or gravity of a man acting in connexion with his muscular 

 effort ; but if any one prefer a different unit or equivalent as the 

 measure of force, it will be easy for him to reduce the following num- 

 bers. 



18. I shall now collect in one view the relative values of the fore- 

 going examples. 



Raised one foot high 

 in one minute. 



A one horse power is equal to = , = c ^ 33,000 lbs. 



The power of one man is equal to 5,500 



The two pairs ofBullocks(8) well angle 14° 31,200 



The one pair do. >^ do. , 18,720 



