Sir William Petty

In Charles II.’s reign there were two main lines along which development was sought. The first of these consisted in the effort to devise ships that would sail better than any before; the second tried to render ships more or less independent of the winds. Sir William Petty experimented in both directions, but without lasting success in either. As is well known, his maritime inventions involved the principle of a catamaran, or double-hulled vessel. The names given, to his several craft by different persons have caused much confusion, but it is clear that he built four if not five sailing vessels of different dimensions, and that in later life he devised a paddle-wheel, which should give ships ‘fresh way at sea in a calm.’ In this latter respect he was not alone, Sir Edward Spragge, the Admiral, having made some fairly satisfactory experiments in 1673, and a towboat having been actually built and established at Chatham in 1683. It was double hulled, with a paddle-wheel between the floats, and, though it was built by the Navy Board officials, it is probable that Petty’s double-hulled sailing vessels had exercised much influence on the design. Tow vessels of various sorts con­tinued to be used at the great ports from this time till the intro­duction of steam, and, although mention of them occurs now and again throughout the eighteenth century, no further reference to them is necessary here.

Petty’s first sailing vessel was built in 1662 at Dublin. He was encouraged throughout by the Royal Society, which, in its turn, was under the patronage of the King, and there is constant reference to letters from him describing his experiments. Unfor­tunately, however, these letters do not seem to have been preserved. The Society decided that the best way in which to compare Petty’s vessel with existing types would lie in organizing a race between her and all comers. Accordingly a committee was formed, con­sisting of such members of the Society as were in Dublin, and it was agreed to offer a prize of a flag to be raced for in the bay. The competitors were four in all: Petty’s vessel, an open barge belonging to the King, a ‘large black pleasure-boat,’ and a man-of-war’s boat. The race was sailed in a strong wind on January 12, 1663, and Petty’s vessel won easily, his crew taking down the flag which was set up at the end of the course, and wearing it in the maintop ‘as admiral of the cylinders.’ Exact details even of Petty’s boat are not available. She was of 1¾ tons burden, carried 600 square feet of sail, which was afterwards increased to 720 feet, and, from her description as the ‘cylinders,’ may be assumed to have had more or less circular cross sections. Birch has an illus­tration of her at anchor, showing that the two hulls supported a complete deck, which, with its rails, looks strangely like a cattle-pen, and that she had two masts and a bowsprit. It would be most interesting to know how she was rigged. The illustration seems to suggest some approach to a schooner, of which more anon; but, unfortunately, we have only the spars to judge by, and the form of hull shown does not inspire confidence, as it certainly does not agree with the known description. It would also be interesting to have some account of the large black pleasure-boat which was to be found at Dublin as early as January, 1663. How did she come there? And did the Irishmen wait till the Restoration before they began to indulge in water sports?

The committee in their report to the Society give a long account of the race, which may be read in Dr. Birch, or, in an abbreviated form, in Mr. Clark’s pages. It must suffice here to say that the boats ran to leeward to the mark-boat, the ‘cylinders’ establishing a long lead; that when they hauled their wind for the beat home the pleasure-boat did best of the other three competitors, since she was loaded with two tons of ballast. The man-of-war’s boat had carried a couple of empty barrels, which she now proceeded to fill, but even this very audacious ballast-trimming did not give her a chance. On the way home the ‘cylinders’ missed stays – the description of the incident seems to suggest that she may have been a lugger – went ashore, and broke one of her rudders; but she succeeded nevertheless in winning very easily, while the pleasure-boat, the most dangerous competitor, broke her boom, and was out of it.

It is curious to find that when the committee presented their report of the race, and asked the opinion of the Society on the invention, the answer was, ‘That the Committee should be put in mind that the matter of navigation, being a State concern, was not proper to be managed by the Society; and that Sir William Petty, for his private satisfaction, may when he pleases have the sense of particular members of the Society concerning his invention.’ This is quite typical of the age, and of that which followed it. All through the seventeenth and eighteenth centuries the jealousy of the Navy Board for professional secrets, and the monopoly of the East India Company, had a very strong effect in forming a rut out of which the art and mystery of shipbuilding emerged with the greatest difficulty. Any improvement must be a matter of indi­vidual effort, and any semi-official or corporate attempt to remedy matters would be looked upon as infringing vested interests, if not as endangering the national welfare. Such a body as the Yacht Racing Association, if we could imagine it and its ‘politics’ to have existed at this early date, would have been promptly muzzled by the threat of divers pains and penalties.

Petty’s second ‘sluice vessel’ was much bigger, being of 30 tons burden, though otherwise seemingly on somewhat similar lines. She carried a quite unnecessary load of 5 tons of guns in deference to the prevailing custom, and had a crew of thirty men. The objections that were raised against the former vessel were laid also against her, that her small grip on the water and large surface exposed to the wind would make her ride exceedingly badly, and that she was likely to break up in a gale. There was proved to be reason in both objections, for she broke adrift in Dublin Bay, drove ashore, and was severely damaged; and a successor of hers was eventually lost at sea. She is best known, however, for her sailing powers, which were good, and are well described in an interesting contemporary newspaper account:

‘Sir William Petty is become famous’ (wrote the Dublin correspondent on 29th June) ‘by the success of his new Invention of the double-bottom’d ship, against the Judgement and Resolution of almost all mankind. When first the ship adventured to Holyhead, she staid there many days before her return, and ’tis pleasant to consider how her adversaries insulted, and having first establisht the conclusion that she was cast away, afterwards discourst the several necessities why it must be so. But her return in triumph has checkt the division of some, and becalmed the violence of others, the first point being clearly gained that she can bear the seas.

‘There has been much adoe in this Town for these last 9 or 10 moneths, about projecting a new way of Shipping, and the successe of it hath been such as that we have been all in faction about it. Several of the Vertuosi have more or lesse approved it, whilst the generality have much denied and reproached it. There have been three several vessels built, and made to saile, all consisting of double Bodies conjoyned, each of severall shapes, dimensions and distances: but the last being the first that seems to be of use, Burthen, Beauty and Accommodation, is the first likewise which I thought fit so particularly to give you an account of.

‘You must pardon me if I hit not the Sea phrases, but in plain English, the matter is thus. On Wednesday this new Device, which the people severally call the Invention, others the Mercury, others the Gemini, others the Castor and Pollux, others the Zabulon and Naphthaly, others the Wit and Money, etc., returned the second time from Holyhead on Wednesday the 22nd instant about five in the afternoone directly against the Wind. She set out from thence with the Ossory Ketch, the most famed of all our three Pacquet Boats, and to which we are most beholding for the speedy transport of our Letters, especially in contrary Winds, but arrived sixteen hours before the said Ketch, whom she ran out of sight and left to Leeward, in a watch or four houres time, whereby we guesse that she outdoes ordinary vessels halfe in halfe.

She undertooke this last Voyage upon a Wager, notwithstanding her Antagonist at the time appoynted (though all full of confidence before) durst not engage against her. Whereby, to speake truth, shee won rather Money than Honour, otherwise then as shee met accidentally means of asserting that too. In her former voyage to Holyhead, she turned in against Winde and Tyde into that narrow Harbour amongst the Rocks and Shipps with such Dexteritie, as many ancient Seamen confessed they had never seen the like. Upon these experiments most gainsayers are now silent, objecting only the excessive charge of building her, and of men to Sayle her, and the danger of separation of her bodies in a Storme. But as to charge, let the Author looke to it, and the Passengers to the danger of separation.’

After the race this ship went round to London, Petty giving a banquet to his crew in October before they started, and taking the opportunity of making a speech. ‘The intention was to send them with a vessel to His Majesty, which, though full of ugly faults and eyesores, being built for a fresh-water lough, and to be carried 8 miles on land, was to outsayle any other vessel whatever, and to endure all the hazards of the troublesome passage from hence to London. Wherefore, he advised them, if they did not believe he should answer these ends, they should not venture their lives to make them and him ridiculous.’ The vessel reached London in safety early in 1664, and though the King was inclined at first to poke fun at Petty, he was prevailed upon shortly to lend him the light of his countenance, and to launch what must have been his third, or, if the Dublin correspondent is to be believed, his fourth ‘sluice-boat.’ The name Experiment was given to this vessel at her launching. Her history is not clear, but it is known that she perished in a gale of wind in the Irish Channel, when many other vessels miscarried. Some of her crew were saved, but seventeen men were lost with her, the date of this event being seemingly 1665. From that time onward the project slept – not only owing to its own misfortunes, but because Petty had lost money in Irish speculations and by the Fire of London. But nearly twenty years later, in 1683, ‘the fit of the double bottom, as he tells us, did return very fiercely upon him. His new vessel, however, performed as abominably as if built on purpose to disappoint in the highest degree every particular that was expected of her.’ We know little of this vessel. Her name was the St. Michael, and she was the last of the type to be built. Whether Petty had made radical departures from the previous design we do not know, but it is interesting to note that Pepys, and Sir Anthony Deane with him, were prepared, not only to dispute every claim which he made on her behalf, but to back their opinions to a substantial amount.

A copy of a model of the Experiment is given in the ‘Life of Petty,’ and shows that the vessel was designed to look, on the broadside, like an ordinary craft. She seems to have been flat-bottomed, but of her rig we know nothing. The model did not satisfy Sir William Petty, for it showed only one deck, whereas the ship had two; but in general aspect it was no doubt at least approximately correct.

Read on … Chapter 3 – Post Restoration