an instrument recommended by Mr Hutchinson as fit to ascertain any alteration in the bottom of a ship, by its hogging or sagging; and also to regulate the stowage of a ship.

"All ships (lays he) of any consequence are built with stauchions fixed from the kelson to the middle of all the lower-deck beams fore and aft, in order to support them in their exact, regular height, as well as the whole frame of the ship in the regular form in which she was built upon the stocks; yet notwithstanding these stauchions, it is proved from experience that our ships bottoms, hitherto, by the prelude of water, and improper stowage, have generally been hogged upwards, or sagged downwards, and most about the midship frame or main body of the ship, which is commonly about the fore part of the main hatchway; which naturally makes it the best place at which to fix the ship's form gauge, where either the hogging or sagging of her bottom may be observed and seen soonest and best, to regulate the stowage of heavy materials to the greatest advantage, so as to keep her bottom nearly in the same form in which she was built.

"The gauge I recommend is nothing more than a narrow plate of iron divided into inches and quarters like the slide of a carpenter's rule. Let this be fixed to the after side of the stauchion now mentioned, with its upper end projecting two or three inches above the stauchion; a groove being cut out for it in the after side of the lower-deck beam, and a mark being made (when the ship is on the stocks) at the part of the beam which corresponds to the o on the gauge. When the ship alters in her shape, the gauge will slide up and down. down in this groove, and the quantity of hogging or fagging will be pointed out on the gauge by the mark on the beam. The stowage may then be so managed as to bring this mark to coincide again with the O, or to approach it as near as we see necessary."