This was the last stage of the evolution of the rifle firing a spherical ball. So long as the spherical ball was retained, spiral grooving offered relatively small advantages over straight grooving; straight grooving offered small advantages over the best smooth-bore muskets. The tedious loading of these rifles and the inefficiency of the system by which windage was eliminated by the force of ramming, are sufficiently set forth by the various writers on early fire arms; and there is small wonder that the value of rifles as military weapons was seriously questioned by the highest professional opinion of the time. The charge of powder had to be carefully varied according to the state of the weather and the foulness of the piece. Care had to be taken that all the grains of the charge poured into it went to the breech end and did not stick to the sides of the barrel. Patches of leather or fustian were carried, in which the ball was wrapped on loading, to absorb windage, lubricate the rifling, and prevent the “leading” of the barrel and the wear which would ensue if a naked ball were used. “Place the ball,” says Ezekiel Baker, “upon the greased patch with the neck or castable, where it is cut off from the moulds, downwards, as generally there is a small hole or cavity in it, which would gather the air in its flight.” The ball, a good tight fit, had to be rammed, in its surrounding patch, right down to the powder: for, if not rammed properly home, an air-space would be left and the barrel would perhaps burst on discharge; at the least, would give an inaccurate flight to the ball. If the barrel were at all worn, double or treble patches were necessary. To loosen the filth which collected in the barrel, and which sometimes prevented the ball from being either rammed or withdrawn, water had to be poured down; not infrequently urine was used. All sizes and shapes of groove were given to the early rifle, and their number depended largely upon caprice or superstition. Seven, for instance, was a number frequently chosen on account of its mystic properties; in _Scloppetaria_ an attempt is made to prove that an odd number has an advantage over an even. So, also, various degrees of twist were used. But in respect of this the evolution followed a definite course. The pitch of the twist necessarily bore a certain relationship to muzzle velocity. With the earliest rifles a fairly rapid twist was given, being rendered possible by the small muzzle velocities employed, and indeed being rendered necessary to ensure stability to the flight of the ball. Then, with the endeavours made, at the end of the eighteenth century, to use higher charges and thereby to extend their range, higher muzzle velocities came into use, and the danger of stripping was then only prevented by the use of low twists. Special devices enabled a return to be made, in the Brunswick and other patterns, to the more rapid twists originally used.