Page:Life of Sir William Petty 1623 – 1687.djvu/148

 There is to be a capstern standing upright betwixt Decks, just in that part of the Ship where the jeer capstern is usually placed. Upon this capstern shall be fix'd a cog-wheele, with the Coggs standing upwards to take hold of the aforesaid Trundlehead.

5. The wheele in which the Coggs are placed, shall have 15 holes, to put so many half barrs in upon occasion as the manner is in Drum Capsterns.

These barrs may be in length about 13 foot from the center of the capstern, if the ship have bredth enough, as I think all ships have, that have 6 foot height betwixt Decks; and then three men may well be placed to every bar.

6. Upon the wast or upper Deck, must be another capstern and crown wheele, with the Coggs turn'd downwards to take hold of the upper part of the Trundle head. So the men betwixt decks heaving one way, the men on the upper deck must heave the other way, to give the Axis and Paddle wheels motion; the like number of Barrs shall be upon ye upper Deck; and ye like number of men: 3 men at each half barr to the 32 half barrs, 96 men in all. And if need should be on any extraordinary occasion, the Barrs may be swifted with a rope running from the end of one Bar to ye end of the other quite round, and one man may heave upon the swifting between ye ends of every Barr; 16 betwixt decks and 16 upon Deck; which added to the 96 makes 128 men.

7. The Paddles and Stemms without side the ship, and the capstern barrs within shall be so ordered, that they may be put in, or taken out in a quarter of an hours time, as occasion shall require. So nothing will remain standing within but the capsterns and Crown wheels, which will take up so little room, as to hinder nothing in the ship, and without will onely remain ye 2 ends of the Axis, with the 7 foot wheel upon each, which may always be kept covered by Tarpaulins made for that purpose.

While the Engine is working, it will hinder the use of 3 or 4 Gunns on each side the ship; but when the paddles and capstern barrs are stow'd, it will neither hinder the use of one Gunn, nor anything else in the ship.

But the best way to evince this point is to have a perfect modell of the Engine, fix'd within a good modell of a fourth-rate Frigat.

Since the first Invention and the said Experiment was made, another use was found out for the Engine, than that for which it first was design'd. And the same being fix'd on two Boats, covered over with a house about 6 foot high and 20 foot square, has bin employed for the Towing of Ships, first wrought with men, and since with horses, over the Barr at Newcastle, and up and down the