Greater length means a greater muzzle energy, higher velocity, and increased power of penetration. The latest guns, too, have shown that the manufacturers have been considering the advisability of effecting a certain amount of redistribution in the thicknesses of the different parts of which the gun is built, notably the tubes, wires, and jackets, and the adoption of a uniform type of rifling. The theory was that the rifling should be increased as the grooves passed down the tube, so that a gradually increasing twist should be given to the projectile, but it is now held that no advantage is obtained by this method, whatever may have been the case in the past, and that the uniform rifling will give better results as to accuracy, muzzle energy and velocity, and inflict no greater strain upon the gun or shorten the “life” of its tube. The trials already made have shown that uniform rifling for modern high velocity guns has resulted in giving greater range and greater accuracy in shooting. The war between France and Germany in 1871 brought machine guns into notice. Great things were expected by the French of the _mitrailleuse_, and some of the patriotic Paris newspapers at the time published glowing prophecies of the number of Germans each gun could be depended upon to kill in a few minutes, with the result that, according to their calculations, there would be no Germans left after a few days to continue the war. But events turned out otherwise; the _mitrailleuse_ failed, and the Germans were victorious. This machine gun was very defective, and served to advertise by contrast the Gatling, Nordenfeldt, Gardner, and Maxim automatic guns, named after their respective inventors. Of these the Maxim has been so improved that it is considered to be superior to any of the others. The machine guns fire, according to the number of their barrels and their calibre, from four hundred to six hundred or more shots per minute, at a range equal to that of the best infantry rifle, and can be sighted with deadly accuracy. CHAPTER X WARSHIPS OF THE TWENTIETH CENTURY