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 6-1/2 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.