OF GUN-POWDER. 47

of an inch in diameter- The musquet thus prepared wasloaded each time with io drachms of fine powder put intocartridges, and with an iron ball ii oz. in weight; the wadswere rammed down with equal force by the fame man.

The experiments began by firing the musquet with thescrew that entirely closed the vent; it was then fired with thescrew ^ inch in diameter; afterwards with that of -r ff , and atlength without any screw. The charges were fired by thehot iron screwed into the breech: the object was a plankplaced at 5 feet from the muzzle of the musquet.

The medium of the penetration of the balls in 24 roundsis as follows :

Inches*

' with the vent entirely closed - - - 6

In the dis- with the vent T ' 5 of an inch in diameter - 8

charges with the vent —• of an inch in diameter - 6-'-

with the vent T 5 ^ of an inch in diameter - 4

It results from this experiment, that when there is novent less powder is fired, and that which does take fire burnsmore slowly. If the large vent be left open, and a sheet ofpaper stretched at 2 feet from it, the paper will be pierced fullof holes by the powder forced through the vent at the explo-sion. Soldiers firing in line are often pricked in the face bygrains of powder driven with force from the musquets ontheir left; the common opinion that these grains are a partof the priming is erroneous.

SECOND PART.

Of the Force of fired Gun-powder.

112. Xt was shewn in the former part of this work thatthe principal properties of powder are subject to many mo-difications, even in experiments conducted with the utmostcare. How much more important and frequent then mustthey be when powder is employed in military operations ;where, from the nature of things, there can neither be somuch attention paid to prevent irregularities, nor so much

accuracy