2d. According to the experiments of M. Lombard, at Auxerre, on guns for land service. 3d. According to the experiments of M. Teixiere de Norbec, at Toulon, on guns for sea service. 4th and 5thly. According to the determination of Mr. Robins and Dr. Hutton. +-------+---------------+--------+-----------------+-----------------+ | | Velocity from | Mean | Velocity from | VELOCITIES. | |Charges| Theory |velocity| experiment. | | | of +-------+-------+ from +- ------+--------+--------+--------+ |powder.| When | When | Theory.| | | | | | | t=31. | t=298.| |Lombard.|Norbec. |Robins. |Hutton. | +-------+------ +-------+--------+--------+--------+--------+--------+ | 1 lb. | 622 | 524 | 573 | 575 | 570 | 640 | 500 | | 2½ | 980 | 836 | 908 | 906 | 940 | 750 | 730 | | 3 | 1072 | 918 | 995 | 989 | 1020 | 969 | 830 | | 4 | 1233 | 1057 | 1145 | 1132 | 1245 | 1069 | 940 | | 6 | 1407 | 1216 | 1312 | 1320 | 1340 | 1215 | 1164 | | 8 | 1564 | 1351 | 1457 | 1425 | 1560 | 1319 | 1348 | |10 | 1581 | 1370 | 1476 | 1475 | | | 1500 | |12 | 1631 | 1421 | 1526 | 1530 | | | 1600 | +-------+-------+-------+--------+--------+--------+--------+--------+ It is the prodigious celerity of expansion of the flame of fired gunpowder, which is its peculiar excellence, and the circumstance in which it so eminently surpasses all other inventions, either ancient or modern; for as to the momentum of these projectiles only, many of the warlike machines of the ancients produced this in a degree far surpassing that of our heaviest cannon, shot or shells; but the great celerity given to them cannot be approached with facility by any other means than the explosion of powder." Dr. Hutton, in conjunction with several able officers of the artillery and other gentlemen, made an extensive course of experiments at Woolwich, at the expense of the British government, by the direction of the then master-general of the ordnance, (the late duke of Richmond,) in the years 1783, 1784, and 1785, which demonstrated the following facts: 1. That the velocity continually increases as the gun is longer, though the increase in velocity is but very small in respect of the increase in length; the velocities being in a ratio somewhat less than that of the square roots of the length of the bores, but somewhat greater than the cube roots of the same, and nearly indeed in the middle ratio between the two. 2. That the charge being the same, very little is gained in the range of a gun, by a great increase of its length; since the range or amplitude is nearly as the fifth root of the length of the bore, and gives only about a seventh part more range with a gun of double length.