Great exhibitions are calculated to effect great good if properly carried out. In that of the English exhibitors at Paris nothing could be more reprehensible, for the jurors left them to the tender mercies of their foreign competitors. In the case of the gun-makers, nothing could be worse, for the two jurymen appointed by the English Government never, I believe, saw a gun, home-made or foreign; and the fact of my obtaining two first-class medals speaks much for the impartiality of our Continental brethren. RECOIL. Recoil varies according to the position of the gun; when fired on the horizontal, the resistance to be overcome is the tendency of the projectile to fall to the earth, and its friction as it moves in a line parallel to the earth. When the muzzle is elevated this resistance is increased, because the force generated by the explosion of the gunpowder has to exert its action more directly in opposition to the direction of the force of gravity; and when this force is exerted in a line directly opposed to the centre of gravity, as it is when the gun is fired vertically, then the recoil is doubled, and is made more painful, because the body resting on the earth cannot yield. A gun fired in the direction of the earth, or in the line of the centre of gravity, would recoil much less (perhaps fifty per cent. less) than when fired vertically; from the very obvious fact, that if the bullet was not kept in position by its friction on the sides of the barrel, it would fall to the ground of itself. “The recoil of a gun is inseparable from a discharge of its contents--on the broad principle that action begets reaction; it is, therefore, only when the ‘kick,’ as it is called, becomes painful, that it is essential to avoid or lessen it. Irregularity in the bore of the barrel is a very common source of violent recoil; _contracted breeches_ also, but more than all, the contraction of the barrel at its centre, occasion recoil, and that of the most dangerous kind: the expanding flame, during its ignition, presses violently to make its way through the contracted to the wider part, thus also destroying the expelling force. ‘Now, action and reaction being equal, it follows, that the weight of the piece being the same, the recoil will be in proportion to the quantity of the powder, and the weight of the ball, or shot; and that with the same charge the recoil will be in proportion to the weight of the piece, or the lighter the piece the greater the recoil.’”--_Essay on Shooting._