TRACT 34,

IN GUNNERY, 1789.

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The short gun was afterwards fired with the same chargeof powder and balls, but blocked up behind the breech, soas to prevent entirely the recoil ; and then the medium ofthe velocities was 1353 feet, being rather less than before,when its sliding carriage was permitted to recoil; but thedifference is not more than may be supposed to happen be-tween any one day’s experiments and another ; so that itmay be safely inferred, that stopping the recoil makes noperceptible difference in the velocity of the ball discharged.

This comparison between the long and short gun beingsettled, the experiments were prosecuted with the long gunalone, that being sufficient for determining the other pointsof enquiry. In the course of a great many days’ experi-ments, as before related, in which the gun was charged withvarious quantities of powder, and discharged at many dif-ferent distances from the pendulum, the medium velocities,among three good ones of every sort, came out as below, inthe following tables, where they are all reduced to the samecircumstances of ball, air, and eprouvette, viz. an exact 3lbball, the height of 30 inches of barometer, and the divisionof 36 on the eprouvette. The tabic of medium velocities inthose circumstances, is as follows.