If the sixteenth century forms the climax of English seamanship, it is the seventeenth century which unfortunately is the anti-climax. Abuses crept into the Navy, so that by the year 1618 a complete reorganisation had to be undertaken, and the bribery, embezzlement, and general corruption had to be stopped so far as was possible. And yet, for all that, there was still being made important progress both in navigation and in shipbuilding. John Napier, in the year 1614, provided his tables of logarithms, which simplified the intricate calculations of navigators. In 1678 was published “The Complete Ship-Wright,” by Edmund Bushnell, which I believe to be the earliest treatise on shipbuilding printed in English. The way the London shipwrights were wont to measure their ships was as follows: They multiplied the length of the keel “into the breadth of the ship, at the broadest place, taken from outside to outside, and the produce of that by the half breadth. This second product of the multiplication they divide by 94 or sometimes by 100, and according to that division, 60 the quotient thereof, they are paid for so many Tuns.” For example, take the case of a ship 60 feet long and 20 feet broad:-- 60 20 ---- 1200 10 ----- 100)12000(120 Ans. 120 tons. But, says this same writer, the true way to measure must be by measuring the body and bulk of the ship underwater. He also gives some of the rule of thumb standards to which they worked. For instance, the mainmast of small ships was three times as long as the breadth of the ship. Thus the ship just mentioned with a beam of 20 feet would have a mainmast 60 feet high. The topmast, in like manner, was two-thirds the length of the lower mast in all cases. The mainyard was two-thirds of the mainmast plus one-twelfth of the mainmast. There is an illustration in “The Mariner’s Jewel,” by James Lightbody, published in London in the year 1695, that shows the method which was employed in launching a ship at that time. It is demonstrated that the vessel was allowed to rest her weight on a cradle and then hauled into the water by means of a crab winch. As there was a paucity of dry docks in those days it was usual, when any painting of, or repairs to, the bottom of a ship had to be carried out, to careen the ship. She was hove down on one side by a strong purchase attached to her masts, the latter having been properly supported for the occasion to prevent their breaking under so great a strain. This was in vogue until about the beginning of the nineteenth century, when the custom of sheathing ships with copper, and thereby keeping a clean bottom for several years, superseded careening.