1.52
NEW EXPERIMENTS, &.C.
TRACT 34.
the quantity of the air’s resistance is computed, by a theo-rem adapted to that purpose.
By comparing the velocities of the long gun and one otthe short ones, with equal charges of powder, but at differentdistances, it may be observed, that the greater velocity ofthe long gun is very soon reduced, by the air’s resistance, toan equality with that of the short one at its least distance;and that this equality takes place the. sooner as the charge ofpowder is smaller. Thus, in the greatest or 3lb charge, thelong gun’s velocity is reduced to that of the short one, whenit has passed through only 95 yards; but in the 2lb charge,in the space of 67 yards; the 1 ilb charge in the space of50 yards ; and the lib charge in the space of about 38 yards:•which fully* accounts for the small advantage in the ranges ofshot by a considerable increase in the length of the piece ;and also how very subject to error any decision must be, indetermining the velocities corresponding with certain lengthsof piece, which is founded on their respective ranges; sincethe irregularities in the shot’s flight, added to the above-mentioned circumstance, must render them very uncertainCriteria, in all cases where high velocities are concerned.
The tables also furnish a further confirmation of the smalladvantage, in point of range, that is obtained, by increasingthe charge beyond what is necessary to communicate a cer-tain velocity to the ball; since the increased resistance tohigh velocities, operates so powerfully, that it is very soondestroyed, or greatly reduced.
Further, by a proper computation from the quantity ofvelocity lost in the several distances, the resistance of the airto a ball of 3’55 inches diameter, moving with several veloci-ties, will be as shown in the last table in art. 193, where itmay be observed that the columns of resistances have pro-perties similar to those that have been before remarked onthe experiments with the smaller balls; which is further re-markable, as, upon trial it is found, that the resistancesagainst the different balls, with equal velocities, are very