ON A NEW ASTRONOMICAL CLOCK. 393 



exceed the forces of the springs ; and resists the 

 motion by forces of friction increasing approxi- 

 mately in simple proportion to the excess of the 



speed above that which just balances the forces of 

 the springs. As long as the escapement-tooth is 

 unrcsisted, the nut-collar is carried round with the 

 quicker motion of the outer tubular shaft, and so it 



