In the latter part of the seventeenth century the cannon were probably 42-pounders, the demi-cannon 32-pounders, and the culverins 18-pounders. Before an effort was made to systematise the armament of ships, hardly any two vessels carried the same number of guns. It was proposed in 1677 that a first-rate should carry twenty-six cannon with eight men to each; twenty-eight culverins, with five men to each; twenty-eight sakers on the upper deck, four on the forecastle, and twelve on the quarter deck, with three men to each saker; and two 3-pounders with two men each. A second-rate should carry twenty-six demi-cannon, with six men to each; twenty-six culverins; twenty-six sakers on the upper deck and ten on the quarter deck; and two 3-pounders, with the same number of men to the guns as a first-rate. A third-rater should carry twenty-six demi-cannon, twenty-six 12-pounders with four men to each; four forecastle and ten quarter deck sakers, and four 3-pounders. The remainder of the complements was to consist of two hundred and ninety-six men, two hundred and sixty-two men, and one hundred and sixty-two men for the three rates respectively, giving grand totals of seven hundred and eighty men, six hundred and sixty men, and four hundred and seventy men. [Illustration: THE CARRONADE AND ITS CARRIAGE. _From Drawings supplied by the Carron Co._] About the beginning of the seventeenth century the practice was introduced and has been retained ever since--with the exception of the later guns, which are indicated by their weight or the diameter of their calibre--of describing the guns by the weight of their shot. A remarkable advance in the science of gun-making was shown when the carronade was introduced by the Carron Company. Briefly, this weapon may be described as a short heavy gun, carrying a heavy shot, and using a moderate charge of powder. It was a wonderfully destructive weapon at short range, and as a broadside gun held its own well into the middle of the nineteenth century. A favourite carronade was that of six diameters, one of which is here illustrated; that is, the length of the bore was six times the diameter of the calibre at the gun’s mouth. These guns were made in two or three patterns. One was the familiar swivel, another had the trunnions below the gun centre so that the gun rested upon them, and the third and most common was that with the trunnions at the sides. The carriages, too, were exceedingly ingenious, being devised to permit of meeting the recoil as well as adding to the facility of handling the weapon, and the sighting arrangements did not leave the gunner much opportunity of going wrong provided he obeyed the instructions.