The early part of the seventeenth century, when James I. was king, saw a remarkable advance in shipbuilding, thanks to Phineas Pett, who dropped the somewhat haphazard rule-of-thumb methods of ship construction and introduced a more or less scientific system of measurement and estimate of weights. In 1610, the _Prince_, or _Prince Royal_, of 1,400 tons, and mounting sixty-four guns, was launched. She is described as “Double-built,” which has been supposed to mean that she had an outer and inner skin and an additional number of beams, etc. This may afford a partial explanation of the fact that though seven hundred and seventy-five loads of timber were estimated to be necessary for her construction, one thousand six hundred and twenty-seven loads were used. Also, as the ship only lasted fifteen years, a possible further explanation of the discrepancy may be found in the suggestion that much of the timber supplied and included in the larger amount was unfit for use. The _Prince Royal_ was “most sumptuously adorned, within and without, with all manner of curious carving, painting and rich gilding, being in all respects the greatest and goodliest ship that was ever built in England.” In 1624 this ship had two cannon-petro, six demi-cannon, twelve culverins, eighteen demi-culverins, thirteen sakers, and four port-pieces. [Illustration: THE “SOVEREIGN OF THE SEAS.” _From the Model in the Royal Naval College Museum, Greenwich._] [Illustration: THE “PRINCE ROYAL.” Designed by Phineas Pett. _By permission of the Elder Brethren of Trinity House._] Good sea fighters as the English had proved themselves to be, they yet were behind the Dutch and French as naval architects. Sir Walter Raleigh, an outspoken critic of the King’s ships and of English merchant vessels, comparing the latter with those of the Dutch, nevertheless admitted that some progress had been made in English shipping. “In my own time,” he writes, “the shape of our English ships hath been greatly bettered. It is not long since the striking of the topmast hath been devised. Together with the chain pump, we have lately added the Bonnet and Drabler.... To the courses we have devised studding sails, top-gallant sails, spritsails and topsails. The weighing of anchors by the capstan is also new. We have fallen into consideration of the length of cables, and by it we resist the malice of the greatest winds that can blow. We have also raised our second decks.” The last improvement was one of the most important, for the space between the decks was cramped, and the lower deck was not much above the water level. The raising of the decks gave the ships more freeboard and increased their seaworthiness, rendered the lower tier of guns more effective by enabling them to be used with less danger from water entering the ports, and gave the men working the guns on the lower tier more head room.