Chap. 4. PHILOSOPHY. 1 55?

velocity ; and let any body E, by being placed in the axisof the canal, hinder the pasiage of the water. It is evi-dent, that the figure of the fore part of this body willhave little influence in obstructing the water’s motion, butthe whole impediment will arise from the space taken upby the body, by which it diminishes the bore of the ca-nal, and straightens the pasiage of the water*. But pro-portional to the obstruction of the water’s motion, will bethe force of the water upon the body E b . Now supposeboth orifices of the canal to be closed, and the water in itto remain at rest ; the body E to move, so that the partsof the water may pass by it with the fame degree of velocity,as they did before; it is beyond contradiction, that the prefi-siure of the water upon the body, that is, the resistanceit gives to its motion, will remain the fame ; and there-fore will have little connexion with the figure of the body c .

2.5. B y a method of reasoning drawn from the fame foun-tain is determined the measure of resistance these compreflectfluids give to bodies, in reference to the proportion betweenthe density of the body and that of the fluid. This shall beexplained particularly in my comment on Sir I s. N e w t o n’smathematical principles of natural philosophy; but is not aproper subject to be insisted on farther in this place.

2.6. We have now gone through all the parts of thistheory. There remains nothing more, but in few words tomention the experiments, which our author has made, both

J Vid. Princ.philos. Lib. II. Lem. p. 314. | b Lemm.d. ( c Ibid. 7.

with.