ON A NEW ASTRONOMICAL CLOCK. 389 



to it. Let friction be properly applied between the 

 shaft and the collar, so that the wheel shall be 

 carried round by the shaft unless resisted by a force 

 exceeding some small definite amount, and let a 

 governor giving uniform motion be applied to the 

 train of wheel-work connected with this shaft, and 

 so adjusted that, when the escapement-wheel is 

 unresistecl, it will move faster by a small percentage 

 than it ought to move when the clock is keeping 

 time properly. Now let the escapement-wheel, 

 thus mounted and carried round, act upon the 

 escapement, just as it does in the ordinary clock. 

 It will keep the pendulum vibrating, and will, just 

 as in the ordinary clock, be held back every time 

 it touches the escapement during the interval 

 required to set it right again from having gone too 

 fast during the preceding interval of motion. But 

 in the ordinary clock the interval of rest is consider- 

 able, generally greater than the interval of motion. 

 In the new clock it is equal to a small fraction of 

 the interval of motion : ^-^ in the clock as now 

 working, but to be reduced probably to something 

 much smaller yet. The simplest appliance to 



