Again, of what practical use had been the discovery of the “solid of least resistance” or of that “cono-cuneus” which Dr. Wallis had investigated with a view to its application to the bows of a ship? A final blow to the scientists was given when the Royal Katherine, a three-decker of 80 guns, designed by the council of the Royal Society, was found so deficient in stability that it was deemed necessary to girdle her. Old Shish had beaten Sir Isaac Newton and all the professors! The impossibility of applying abstract scientific principles to so complex a machine as a sailing ship, moving in elements so variable as air and water, was patent to everyone. The attitude of the professional may be judged from the resigned language of William Sutherland, a shipwright of Portsmouth and Deptford Yards, who in 1711 published his Ship-builder’s Assistant:
“Though some of our preceding Master Builders have proposed length as expedient to increase motion, yet it has seldom answered; much extra timber is required to make them equally strong. Besides, if the solid of least resistance be a blunt-headed solid, extreme length will be useless to make cutting bodies.”
Again, in connection with the dimensions of masts:
“Though several writers say, that the velocities are the square roots of the power that drives or draws the body; from which it should be a quadruple sail to cause double swiftness. Hence, unless the fashion is adapted to the magnitude of the ship, all our Art can only be allowed notional, and the safest way of building and equipping will be to go to precedent, if there be any to be found. But this is a superfluous caution, since ’tis very customary, that let a ship be fitted never so well by one hand, it will not suit the temper of another. Besides, the proper business of a shipwright is counted an very vulgar imploy, and which a man of very indifferent qualifications may be master of.”
Science was, in short, discredited. The corporation of shipwrights had disappeared, not long surviving the fall of the house of Stuart. No master-builder had succeeded the Petts and the Deanes having sufficient influence and erudition to expose the faulty system under which warships were now built, English shipbuilding had once more become a craft governed entirely by precedent and the regulations. The professor was routed, and the practical man said in his heart, There is no knowing what salt water likes.
Yet the science of naval architecture was at the dawn. Not in this country, but in France, in the early part of the eighteenth century, research and inquiry received such encouragement from the State that it conferred on their fleets a superiority of design which they retained for long: a superiority which enabled them, in the guerre de course which was developed after La Hogue under the intrepid leadership of men like Jean Bart, Forbin, and Duguay-Trouin, to strike us some shrewd blows.
We propose to summarize as briefly as possible the principal events which mark the evolution of the scientific side of naval architecture.
A mere enumeration of the names and works of the men who chiefly contributed to the discovery of the true natural principles underlying the performance of sailing ships would suffice to show the debt owed by the world to French effort, and the tardiness with which this country faced the intellectual problems involved. In the year 1681 a series of conferences was held at Paris on the question of placing the operations of naval architecture on a stable scientific basis; but before that date, in 1673, Father Pardies, a Jesuit, had published the results of his attempts to calculate the resistance of bodies moving in fluids with varying velocities. In ’93 the Chevalier Renaud and Christian Huyghens were engaged in public controversy on the merits and deficiencies of Pardies’ laws. In ’96 James Bernouilli entered the lists on Huyghen’s side, and in the following year a remarkable work appeared from the pen of another Jesuit, Paul Hoste, professor of mathematics at Toulon. Father Hoste, having noticed the frequency with which vessels of that time required girdling, had put the question, why they should not be built initially with the form which they had when ultimately girdled. The replies given him being unsatisfactory, the professor investigated a whole series of problems: the relation between speed and resistance, the effect of form on resistance, stability, stowage, the properties affecting pitching, and the best form of bow. Though incorrect in much of his theory, he had admittedly a great influence on later research. He was followed, in 1714, by John Bernouilli, professor at Basle, whose investigations were purely theoretical. And then, a few years later, M. Bouguer made his great discovery of the metacentre, that all-important point in space whose position in a ship, relatively to its centre of gravity, marks with precision the nature of the vessel’s stability.
A treatise by Euler, entitled Scientia Navalis, was published in 1749, and a little later, stimulated by prizes offered by the Société Royale des Sciences, Don G. Juan in Spain, Euler in Russia, and Daniel Bernouilli in Germany, all published the results of their investigations into the forces acting on a rolling ship. Euler’s contribution was especially valuable. Treating the ship as a pendulum he laid down two definite rules for the guidance of shipbuilders, (1), not to remove the parts of a ship too far from the longitudinal axis, (2), to make the most distant parts as light as possible.
Up to this time the discoveries of the mathematicians had had little practical effect on shipping. The abstruse form in which new truths were published, and the lack of education of the shipbuilders, prevented that mutual collaboration which was necessary if the art of shipbuilding was to benefit by the advances of science. Soon after 1750, however, a succession of able men, possessed of imagination and initiative, led inquiry into practical channels, and by actual trial proved, incidentally, that much of the accepted theory was faulty. The Chevalier de Borda, a naval captain and a member of the Academy of Sciences, investigated with models the resistance of fluids to motion through them, and enunciated laws which shook confidence in current beliefs. The result was a commission from the government to three eminent men, M. D’Alembert, the Marquis Condorcet and the Abbé Bossut, to report on and continue de Borda’s investigations. The report, read by the Abbé before the Academy in 1776, confirmed generally de Borda’s theories, and revealed new problems—in particular, the alteration in shape of the free water surface and the effect of wave resistance, the latter of which was ultimately to be solved in this country by Mr. W. Froude—that required investigation. The circumstances of this commission illustrate the enlightened interest of the State in the advancement of knowledge, significant testimony to which was paid by Abbé Bossut. “M. Turgot,” he said of the Comptroller-General of Finances, who took responsibility for it, “who is not only an admirer of the sciences, but has pursued the study of them himself amidst his numerous important official functions, approved of our intentions, and granted every requisite for prosecuting them.”