all the shots are close together, you may be sure the gun shoots well, though they may be at considerable distance from the bull’s-eye.  That would only prove that the line of sight was not coincident with the line of fire, which can be easily rectified by moving the forward sight to the right or left, according as the variation was on the one side or the other.  Having fired your string of ten shots, take a pair of dividers, and, with a radius equal to half the distance between the two hits most distant from each other, describe a circle cutting through the centre of each of those hits.  From the centre of this circle measure the distance to each of the hits, add these distances together and divide the sum by ten, and you have the average variation, which ought not to be over two inches at the utmost, and if the gun is what it ought to be, and fired by a good marksman, would probably be much less.  This is a sufficient test of the precision for that distance, and the same method may be adopted for longer ranges.  But if the gun shoots well at one hundred yards, its capacity for a longer range may be proved by its penetrating power.  Provide a number of pieces of seasoned white-pine board, one inch thick and say two feet long by sixteen inches wide.  These are to be secured parallel to each other and one inch apart by strips nailed firmly to their sides, and must be so placed that when shot at the balls may strike fairly at a right angle to their face.  Try a number of shots at the distance of one hundred yards, and note carefully how many boards are penetrated at each shot.  The elongated shots are sometimes turned in passing through a board so as to strike the next one sideways, which of course increases the resistance very greatly, and such shots should not be counted; but if you find generally that the penetration of those which strike fairly is not over six inches, you may rest assured the gun cannot be relied on, except in a dead calm, for more than two hundred yards, and with anything of a breeze you will make no good shooting even at that distance.  Nine inches of penetration is equal to six hundred yards, and twelve inches is good for a thousand.

A striking proof of the prevailing ignorance of scientific principles in rifle-shooting is afforded by the fact that it is still a very common practice to vary the charge of powder according to the distance to be shot.  The fact is, that beyond a certain point any increase of the initial velocity of the ball is unfavorable both to range and precision, owing to the ascertained law that the ratio of increase of atmospheric resistance is four times that of the velocity, so that, after the point is reached at which they balance each other, any additional propulsive power is injurious.  The proper charge of powder for any rifle is about one-seventh the weight of the ball, and the only means which should ever be adopted for increasing the range is the elevating sight.