[ lo ] 



foldered with filver into a tempered piece of fteel g, having three 

 levelling fcrews h h h, carefully tapped through it. The points 

 of thefe tempered fcrews are rounded and lie in beds formed 

 for them in I, a piece of fteel -jZ_ of an inch broad en the upper 

 fide •, the lower part being rounded, this is very firmly leaded 

 into a piece of flatuary marble K, about two hundred weight, 

 firmly inferted in the wall, fo as juft to admit the ftcel piece I 

 to pafs through the back of the clock cafe : The pendulum 

 being entirely detached from the clock and fufpended on the 

 diamond, and the whole upon the wall. Before the clock was 

 applied, it continued vibrating twenty-feven hours in this de- 

 tached ftate as a fimple pendulum. I have applied the main- 

 taining power from the movement by a well-tempered and po- 

 lifhed fteel cylinder -j-V of an inch diameter, firmly fcrewed to 

 the crutch through the opening in the brafs collar L ; in this 

 opening I have fixed two pieces of fapphire, of which this is the 

 feclion O, the cylindrical fides which the hard fteel cylinder 

 above-mentioned ads againft being well polifticd, the contad is 

 lineal. To the back of each of thofe pieces of fapphire I have fitted 

 two fcrews o, o, tapped through the brafs collar L, which firmly 

 embraces the pendulum rod. By thefe fcrews the pieces of 

 fapphire are accurately adjuftedtothe fteel cylinder, fo that the 

 power is applied, without the fmallcft fhake or lofs of force, 

 exadly in the line of the centres of ofcillation, gravity and fuf- 

 penfion. 



An account of a clock where the maintaining power is applied 

 immediately from the efcapement wheel to the axis of the pen- 

 dulum rod, without verge, crutch, or any other agent. — I cut a 



notch 



