PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 



445 



The shrinkage of the material, and the consequent shaky condition of 

 ordinary wheels exposed to a very dry atmosphere, are too well known to 

 require elaborate remark, and the desirability of completely repairing a 

 wheel damaged by a shot, or otherwise, without delay, is obvious. 



r 





Certain parts of the wheels of gun carriages are frequently entirely 

 destroyed by a shot from the enemy, while other parts are unaffected. By 

 simply moving the carriage so much as will partially revolve the wheel 

 and bring the injured part on the upper side, if it is not already there, I 

 can, with the aid of a suitable wrench, remove the injured parts of my 

 wheels and insert new parts, which, after a proper setting up of the bolts, 

 make the M'heel as complete as before. I have recently demonstrated, in a 

 practical test before United States officers, that I can singly repair the 

 wheels of artillery carriages, constructed according to my invention, faster 

 than a man with an axe can destroy them. 



The figure represents a side elevation and cross section of a wheel, con- 

 structed according to this portion of my invention. Figure 45 is a cross 

 section of the wheel in the line UU in figure 44. Figure 46 is a plan view 

 of a portion, or more exactly a cross section, on the line FF in figure 44. 

 Figure 4t is a cross section on the line TFTFin figure 44. 



