length at main rail to inside of plank, or "moulded"; 25 feet 6 inches moulded beam, allowing 3 inches for plank (as usual in a ship of this size and date); and about 15 feet 4 inches moulded depth at side, keel rabbet to underside of upper deck. The bulwarks were drawn at 28 inches height. Next, the mast positions were decided by prorating from the plan of the Ohio the position of each mast from the fore perpendicular and then modifying these positions slightly by use of masting rules contained in M'Kay's book[20] of 1839.

Since it appears that the Savannah may not have been purchased for conversion to a steamer until near the date of her launch and because of the lack of identification of the lithograph referred to by Collins, the statement that the mainmast was placed farther aft than normal was rejected. At launch her mast partners would have been in place and the deck laid. Any alterations in the position of the mainmast then would have made it impractical for the owners to demand them of the builders without heavy additional expense. In addition, the plan, as it was developed, indicated no need for such alteration.

The plan of the engine, drawn to the same scale as the profile plan, was shifted about on the lower deck in the hull profile to determine where the engine and side paddle wheel shaft might be located. A little experimentation and study made it certain that the proper location could be estimated within a foot or so, to scale, as to fore and aft positions. The after end of the cylinder, and its piping, had to clear the mainmast by at least 9 to 10 inches to allow removal of the cylinder head for inspection and repair. The position of the wheels, stack, and masts in Marestier's sketch of the ship make it certain that the engine was on the lower deck, abaft the paddle wheel shaft. Due to differences between the dimensions stated by Marestier and in the Vail account books and what the graphic scale in Marestier's engine drawings produce, the exact dimensions of the engine are uncertain. Nevertheless, they can be approximated with enough accuracy for our purpose. As a result of this treatment, it seems fully apparent that the engine was abaft the paddle wheel shaft, with frame extending abaft the mainmast on the lower deck; there does not appear to be a practical alternative in the light of the available evidence. This matter will be referred to again.

The size of the cylinder and its valve chest and the inclined position of the cylinder indicate conclusively that the valve chest was in the mainhatch, which would normally be just forward of the mainmast. Even then, the after flange of the cylinder would just clear the lower deck, allowing 6 feet between decks, as in the Ohio. The cylinder would have been about 6 feet long; the graphic scale indicated 6 feet 3 inches. The diameter of the cylinder plus height of valve chest seems to have been 5 feet 9 inches to 6 feet. Because of the use of the crosshead and a connecting rod, pivoted at crosshead, the oscillating rod (or pitman) and piston together equalled twice the stroke plus allowance for stuffing box, crosshead, and pitman bearings. Therefore, the engine's over-all length, from head of cylinder to the centerline of the side paddle wheel shaft, could not have been much less than 15 feet 9 inches, and probably as much as 16 feet 2 inches, thus making the length at extreme clearance of crank throw as much as 19 feet. These dimensions indicate that the centerline of the side paddle wheel shaft must have been from 38 to 39 feet from the forward perpendicular. It is not clear how the wheel shaft was mounted in the vessel. Taking into consideration her depth and her reported draught, light and loaded, the Marestier sketch, and the hull structure then used, it seems reasonable to place the centerline of the shaft (which seems to have been about 7 to 8 inches square) about 12 inches above the upper (or spar) deck to allow proper dip of the blades. This position would have given proper blade immersion at the mean draught of 13 feet.

In order to get the engine below deck, and to get the boiler or boilers placed, it was necessary to cut a large opening in the two decks. It may be assumed that this opening was big enough to take the cylinder, without valve chest, and also the boilers, which went into the hold. Taking the proportions of other boilers as shown by Marestier, it has been estimated that the Savannah might have had a boiler about 18 to 20 feet in length, 7 to 8 feet wide, and 6 to 61/2 feet high at firebox. The form might be the same as that of Fulton the First, illustrated in the translation of Marestier's report.[21] However, since the Russian descriptions[22] indicate there were two boilers, each measuring 6 feet in diameter and 27 feet in length, the two boilers would have reached past the mainmast if they were located in the same manner and in the same place as the boilers shown in the illustration of Fulton the First. Consequently, if the Russian description is accepted, there would have been a need for longer fuel (coal) spaces in the wings.

The boilers, then, were the largest piece of equipment to be passed through the decks; for this an opening (estimated to have been about 101/2 feet wide and 81/2 feet long) probably was cut through both decks about 3 feet forward of the main hatch, which was commonly a little forward of the mainmast. The boilers could then have been lowered, after end first, into the hold. The opening in the lower deck could then have been closed, except for a small hatchway perhaps, and the steam cylinder let down to the lower deck and moved aft into position. To allow the crosshead to reach its maximum travel, the opening in the upper deck would have been about 101/2 feet wide—the over-all width of the engine frame—and would have been left open, inside the deckhouse.

The width of the boilers might be particularly important because it would determine the deadrise at floor in the hull. The apparently precise dimensions of the boilers given in the Russian description were utilized to arrive at a suitable hull form. Both a single boiler and a double boiler (as described in the Russian accounts) were placed in the hull to assure the correct space estimates.

Since the engine, as shown by Marestier, had an air-pump cylinder alongside the steam cylinder (with the pistons of both attached to the crosshead), it is evident that a condenser was employed. This condenser would not have been much larger than the air-pump cylinder. It may have been placed under the side paddle wheel axle on the lower deck, but its mode of operation is unknown. Possibly it was of the jet type, with pumps operating off the paddle wheel axle and with a return of condensate from a hot well into the feed water line. A number of possibilities could be mentioned, all speculative. However, there was no doubt that this equipment could be properly installed in the reconstructed hull, either on the lower deck or in the hold.

Two questions have been raised as to machinery arrangement—whether the engine, and boilers also, might have been forward of the wheel shaft, and whether the wheel shaft was above or below deck. If the engine were placed forward of the wheel shaft, the