of Fluids, compared with the best Experiments, 259 



responding to the same area and velocity was '846 ounce. The 

 mode adopted by Dr. Hutton to reduce for the edge of the 

 plane is not quite correct, as it obviously has an unequal ef- 

 fect at the different angles. (Art. 12.) 



30. In comparing the resistance of bodies of different forms, 

 Dr. Hutton obtained the following ratios : 



It will be remarked, that in air as in water, the hemisphere 

 with the convex side foremost differs most widely from the 

 result of calculation. The sphere is very near, and the near 

 coincidence of the actual resistance, as well as the ratio, is 

 worthy of notice. 



The resistance of a ball two inches in diameter was found 

 by experiment to be -163 ounce at a velocity of twenty-five 

 feet per second. By calculation I find its resistance '1655 

 ounce at that velocity, — a difference of only -£j in excess. 



31. Col. Beaufoy* made some experiments on the resistance 

 of air on bodies of different shapes, and published a table of 

 the resistances. When the area of the base is one superficial foot 

 the force is in ounces ; and taking the line corresponding to a 

 velocity of twelve feet per second, I have added the numbers 

 my mode of computation give in these cases. % 



In these comparisons the calculated numbers are in defect, 

 and the ratios are not very different. 



32. Returning to Dr. Hutton's experiments f, I must next 



* Annals of Philosophy for 1815, vol. vi. p. 277. 

 • t Tracts, vol. Hi. p. 230, where the tentative formula of Dr. Hutton are 

 given. 2 L 2 show 



