NO. 3 I.AXOLEY memoir on mechanical flight 235 



shells are water jacketed they then do not expand as uracil as the cast-iron 

 liners, and this causes the latter to become " out of round " because of the 

 compression strains produced in them when trying to expand more than the 

 steel shells. As past experience had shown, however, that it was possible to 

 keep the liners tight in small cylinders, it was believed that by faking proper 

 care in the construction there would be no difficulty in this respect with the 

 cylinders of this larger engine. 



In carrying out these plans, however, of making the cylinders of steel, 

 numerous constructional difficulties were encountered which could not be fore- 

 seen when the design was made. Had they been foreseen, provision for obvi- 

 ating them could easily have been made. As will be seen from the drawing, 

 Plate 78, the engine cylinders consisted primarily of a main outer shell of steel 

 one-sixteenth of an inch thick, near the bottom end of which was screwed and 

 brazed a suitable flange, by which it was bolted to the supporting drum or crank 

 chamber. These shells, which were seamless, with the heads formed integral, 

 were designed to be of sufficient strength to withstand the force of the explo- 

 sion in them, and, in order to provide a suitable wearing surface for the pis- 

 ton, a cast-iron liner one-sixteenth of an inch thick was carefully shrunk into 

 them. Entering the side of the cylinder near the top, was the combustion cham- 

 ber, machined out of a solid steel forging, which also formed the port which 

 entered the cylinder and was fastened to it by brazing. The water jackets, 

 which were formed of sheet steel .020 inch thick, were also fastened to the cyl- 

 inder by brazing, and it was in connection with the brazing of these water jack- 

 ets that the first serious difficulty was met in the construction of the engine. 

 In the first place, as the jackets were of an irregular shape and of a different 

 thickness of metal from the walls of the cylinder to which they were joined, 

 the expansion and contraction due to the extreme heat necessary for properly 

 brazing the joints caused such serious strains in various and unexpected direc- 

 tions that it was only by exercising the very greatest care and patience that 

 a completely tight joint at all points of the jacket could be secured. In the sec- 

 ond place, the size of the cylinders and the consequently large extent of water- 

 jacket surface, complicated the problem. The maintenance over this large sur- 

 face of the extreme heat necessary for brazing involved discomfort and, indeed, 

 actual suffering to the person engaged in the work, and much care and skill 

 were demanded in so distributing the heat that the temperature of the surface 

 of the jackets would be uniform enough to prevent serious strains from expan- 

 sion and contraction. As no workman could be found either competent to do 

 the work or willing to undergo the personal discomfort, the writer was obliged 

 to do all this brazing work himself. Besides the difficulties due to the expan- 

 sion and contraction of the jackets while they were being brazed, the greatest 

 care had to be exercised to avoid heating the cylinders so hot as to weaken the 



