418 



MEMOIR OF DANIEL TREADWELL 



forward wheels are placed nearer each other than the hind wheels, and to per- 

 mit this arrangement the sides of the carriage are cut away upon the outside, as 

 shown in Fig. 3. Through the sides of the carriage directly under the gun is 

 passed an iron shaft, a A ; upon this shaft is arranged a flat band, B b, made of 



rope bound together by a weft of small line (the weft not shown in the drawing). 



The section (Fig. 3) shows the band as cut through when wound upon the shaft. 



The band is of one piece of rope doubled to make eight or ten strands, and is 

 secured to the shaft a by passing the doublings through holes in it. Iron pins 

 are passed through each doubling, which prevent its being drawn from the shaft. 

 Through the doublings at the other end of the band an iron bolt is passed, cc. 

 This bolt likewise passes through three links, ddd. These links are connected 

 by another bolt to the shackle, E e, which is fastened to an eye-bolt in the side 

 of the ship. On one end of the shaft are the friction plates, f, which are secured 

 by projections on them to grooves in the shaft, so that they must turn with it, 

 but can slide on it to or from each other. Between each two of the plates is 

 another plate, g, Figs. 2 and 3. h h are two springs, one on each side of the 

 plates. These and the plates g are fastened by a bolt, k, to the carriage, so that 

 they cannot turn on it, but the shaft A moves freely in holes made through 

 them. The springs are drawn together by screw-bolts. The object of the appa- 

 ratus is to make a powerful friction to resist the turning of the shaft A and the 

 unwinding of the band b, and consequently to restrain the recoil of the gun and 

 carriage when fired. The operation of this is as follows. Let the gun and car- 

 riage be carried forward so that the band bb shall be wound firmly upon the 

 shaft a a, one end of the band being fixed to the shaft, as before described, and 

 the other end to the eye-bolt ; then let the springs hh be drawn together by 

 the screw-bolts so that the sides of the plates or disks f f and G G, Figs. 2 and 3, 

 are pressed against each other. Now, when the gun is discharged, the carriage 

 cannot move backward without unwinding the band bb, by which the shaft A a 

 must be turned round. This must cause the Dlates or disks ff to revolve ; 



but as the plates g g are connected by the bolts 1 1 with the springs, which are 

 prevented from turning by the stud k, the plates ff in revolving must rub 

 their sides against the sides of the plates gg, and this friction must resist the 

 turning of the shaft a a, the unwinding of the band b b, and, consequently, 

 the recoil of the gun and carriage. The resistance may be increased by increasing 

 the number of plates and the pressure of the springs. To relieve the friction 

 and permit the shaft a a to turn, the lever o. Fi*s. 1 and 2, has on its lower 





