40 BULLETIN 173, U. S. NATIONAL MUSEUM 



frame erected over the cylinder. A connecting rod extended down- 

 ward from each side of the cross head to the aft end of a bell-crank 

 lever, one of which was located on each side of the cylinder. The bell 

 cranks were triangular trusses constructed with a long horizontal 

 lower member pivoted at a point about a foot forward and slightly 

 below the bottom of the cylinder. This member extended aft so that 

 the end that was connected to the cross head was approximately 

 opposite the center of the cylinder and under the cross head. The 

 same member extended forward from the pivot about the same dis- 

 tance and the forward end was heavily weighted to counterpoise 

 the weight of the connecting rod. Integral with the lower horizontal 

 member of the lever, perpendicular to it, and rising from it at the 

 pivot point was a short arm, which formed, with the lower member, 

 a right-angle bell crank. From the top of the short member a long 

 connecting rod extended forward to a crankpin in the side of the rim 

 of a large gear wheel, which meshed with and turned a larger gear 

 on the paddle-wheel shaft. From a point forward of the pivot of 

 each lever a connecting rod extended upward to the cross head of an 

 air pump and to the end of a vibrating beam from which motion was 

 taken to operate two other pumps, which were probably bilge and 

 boiler feed pumps. A large flywheel was mounted directly over the 

 keel on the paddle-wheel shaft. The valves and valve gearing of the 

 engine are not detailed, and all that can be said is that there was a 

 valve chest at either end of and on the aft side of the cylinder con- 

 nected together by a pipe on the starboard side. De Witt states that 

 "the valves of the cylinder were poppet valves operated by the clack 

 gearing, then in use." The valves of the engines in the model of the 

 Glei'mont in the water craft collections of the Museum are indicated 

 as having been operated by hand. Drawing 7 attached to Fulton's 

 U. S. Patent Specification of 1809 from a copy in the Boulton and 

 Watt manuscript in the possession of George Sangyl, Birmingham, 

 England, first published in Robert Fulton^ Engineer and ArtiM^ by 

 H. W. Dickinson, London, 1914, indicates a practically identical 

 arrangement of machinery. This drawing shows a plug tree, for 

 actuating the valves, connected to the vertical arm of the bell crank 

 by means of a flexible cord or chain turning over a guide pulley. 

 The plug tree was raised by the pull of the cord and returned by its 

 own weight. 



The boiler was a return-flue cylindrical shell boiler set in brickwork. 

 The brickwork formed the furnace under the forward end of the 

 shell and a long narrow flue under it to the back of the boiler. The 

 grates were horizontal. The chimney was at the front of the boiler 

 (the forward end) and was supported on a brick column, which also 

 enclosed the front smoke box. An inclined chute through the brick 

 column permitted fuel to be put upon the grates. The shell of the 



