NEW EXPERIMENTS

TRACT 34.

30$

supply that defect, having used cannon balls of above twentytimes the size, or from 1 pound to near 3 pounds weight.These are the only experiments, that I know of, whichhave been made in that way with cannon balls, though theconclusions to be deduced from such a course, are of thegreatest importance, in those parts of natural philosophywhich are connected with the effects of fired gunpowder : nordo I know of any other practical method besides that above,of ascertaining the initial velocities of military projectiles,within any tolerable degree of the truth ; except that of therecoil of the gun, hung on an axis in the same manner as thependulum ; which was also first pointed out and used by Mr.Robins, and which has lately been practised also by Ben-jamin Thompson, Esq. (now Count Rumford) in his veryingenious set of experiments with musket balls, describedin his paper in the Philosophical Transactions for the year1781. The knowledge of this velocity is of the utmostconsequence in gunnery: by means of it, together withthe law of the resistance of the medium, every thing is deter-minable which relates to that business ; for, as remarked inthe paper above-mentioned on the first experiments, it givesus the law relative to the different quantities of powder,to the different weights of balls, and to the different lengthsand sizes of guns ; and it is also an excellent method oftrying the strength of different sorts of powder. Besidesthese, there does not seem to be any thing wanting toanswer every inquiry that can be made concerning theflight and ranges of shot, except the effects arising fromthe resistance of the medium.

2. In that course of experiments were compared, theeffects of different quantities of powder, from 2 to 8 ounces;the effects of different weights of shot; and the effects ofdifferent sizes of ball, or various degrees of windage,being the difference between the diameter of the shotand the diameter of the bore : all of which were found toobserve certain regular and constant laws, as far as theexperiments were carried. And at the end of each day’s