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notch in the pendulum rod deeper than its axis, (fee the profile, 

 Fig. III.) and in that opening at k, and in that part on a plate of 

 brafs fixed firmly by fcrews, two pallets r and s, reprefented larger 

 at Z below, and by the efcapement wheel P, with pins i, 2, 3, 4, 

 5, 6, &c. made of very hard drawn brafs wire inllead of teeth, 

 I applied the maintaining power exa611y in the line of the centres 

 of magnitude, ofcillation, fufpcnfion, motion and gravity. This 

 appears to me the moft fimple and perfed method of applying 

 the maintaining power to pendulums that has hitherto been 

 thought of, and if perfedly executed with ruby or fapphire 

 pallets, and hard fteel pins well finifhed in the wheel, the point 

 of fufpenfion made perfedly immoveable, and the maintaining 

 power perfedly uniform, then perhaps the faireft trial may be 

 given to different pendulums. 



On fhewing my clock made in this way to an ingenious gen- 

 tleman from London, he told me he faw one executed on the fame 

 principles in England. I went to fee it, and found it fomewhat 

 like mine, but the maker had not thofe matters in view that I had, 

 as he did not communicate the power at the centre of the rod, 

 but on its external part, by which means much of the power 

 was loft, and the remainder gave the pendulum an undulatory 

 motion which added confiderably to the fridiion, and totally de- 

 ftroyed the ifochronifm *. 



* Since thefe clocks were made, I conftrufted another very fimple one, in which 

 I made the pendulum to vibrate at right angles with the plane of the efcapement 

 wheel : this method promifes fome material advantages, particularly iu large clocks. 



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