A few glimmerings of the complicated subject of naval architecture became evident in the years that included and followed “the age of discovery,” and ships, or at least _some_ ships, were “designed” by men who made a study of them. The designs, however, were largely little more than the transfer of rule-of-thumb methods to paper, and a real understanding of the subject was still far distant. Phineas Pett, during the 17th Century, designed many ships for the British Navy, and from these designs the ponderous ships of later days developed. In France, however, naval architecture seems to have been a better-understood art than in England, for many times British designers improved their ships after studying captured French ships. The designers in England for many years were guilty of one error in particular which, while later corrected, proved to be the cause of the loss of several of their very greatest ships. This fault was the placing of the lowest tier of gunports so close to the water that when the ships were under a press of sail the ports on one side or the other, and they were not watertight even when closed, were under water. During the reign of Henry VIII, a British ship named the _Marie Rose_ heeled over when getting under way, and the ports, which were open and were only sixteen inches above the water when she was on an even keel, permitted the water to enter in such quantities that she sank. Years later Sir Walter Raleigh wrote that this defect was being corrected, yet later still the _Royal George_ was lost because of the same fault. It is interesting to quote a few lines of Raleigh’s writings on ship design. Commenting on improvements in lines he said that ships with these improvements “never fall into the sea after the head and shake the whole body, nor sinck a sterne, nor stoope upon a wind.” He also suggested that the lowest tier of gunports should not be less than four feet above the water. Furthermore, he objected to the high sterncastles which made the ships of the time both unseaworthy and ridiculous. Modern scientific naval architecture can properly be said to date from the latter part of the 17th Century, for it was then that the first studies were made of the passage through the water of various shaped hulls. Before this, ships were built and if they were successful were copied; if unsuccessful they had less influence on later design. Now began a study that has been carried down to to-day, and scientific deductions began to be made, and upon these investigations and the results of them an important part of naval architecture has been founded.