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SMITHSONIAN CONTRIi'.l I'll i.NS To KNOWLEDGE 



vol. 27 



joint where the explosion chambers were joined to the cylinders, which, of 

 course, had been brazed before the jackets were fitted to them preparatory to 

 brazing them. 



Another great difficulty was that the ring which encircled the cylinder near 

 the middle of its length, and which formed the bottom part of the water jacket, 

 expanded very much more than the cylinder itself, so that, if it was brazed to 

 the cylinder before the jacket was brazed to it, the heat of brazing the jacket 

 to the ring would cause the ring to break loose from the cylinder; while if the 

 ring was not previously brazed to the cylinder, but was brazed after the jacket 

 had been brazed to it, the very much greater heat required for brazing the ring 

 to the cylinder caused the spelter to burn out of the joint between the jacket 

 ami the ring. Furthermore, it was found very difficult to braze the two joints 

 at the same time, since in brazing the ring to the cylinder it was best to have 

 the cylinder in an inverted vertical position, so that the spelter could be made 

 to flow evenly around the ring and form a fillet against the wall of the cylin- 

 der, while in brazing the jackets to the ring it was best to have the cylinder 

 in the reverse vertical position or lying on its side so that the spelter could 

 properly flow into this joint. Finally, however, after what proved to be most 

 exasperating and tedious work, the live cylinders necessary for the engine were 

 completed and a series of tests was immediately made. During the course of 

 these tests the water circulation became obstructed in several instances, and the 

 consequent high temperature to which the cylinders and jackets were raised 

 caused severe strains in the jackets which, in turn, produced breaks in the 

 brazed joints. These breaks had to be rebrazed, and in brazing them it was 

 necessary in almost every case to remove the cast-iron liners and rebraze "the 

 entire jackets from start to finish, as the application of the intense heat neces- 

 sary for brazing at any one point produced such severe strains that before the 

 break which was being repaired could be completed other breaks developed at 

 various points of the jacket. It was, therefore, necessary to get the whole jacket 

 up to a fairly uniform heat and complete the brazing while it was in this con- 

 dition, and then keep the whole cylinder at a uniform but gradually decreasing 

 temperature until it had sufficiently cooled off. 



On account of these troubles with the water jackets and the cylinders, it 

 was decided to build some extra cylinders, not only because past experience 

 had surest ed improvements in detail in the construction of the jackets, which 

 would prevent to a large extent the great troubles which had been met with 

 in the brazed joints, but also to insure having sufficient cylinders to enable the 

 engine to be always in working condition, even though several of the cylinders 

 might be out of commission from slight imperfections in the jackets or at other 

 points. "While the construction of these new cylinders involved a repetition of 

 the arduous task of brazing, yet the minor improvements which were introduced 



