()4f EFFECT OF ATTU/lCTION ON THE GOING OF CLOCKS. 



about 12lb,, and that of the going weight 28lb. From the forci- 

 ble swing or motion of this pendulum, it was thought, that 

 attraction would scarcely have any influence here; however, 

 the weight, when opposite to the peiiduluto ball, brought the 

 arc of vibration gradually in to three degrees ; but on the weight 

 leaving or getting below the pendulum ball, the former arc of 

 three degrees six minutes was regained. 



There are few clock-makers, who may not in the course of 



their experience have had a great deal of trouble with old 



Month clocks month clocks, much vexation and running after them, on 



troubIc"some sccoii"^ of their stopping ; and this apparently from causes inex- 



even stoppiiig, plicable and undiscoveiable ; and with the greatest difficulty, 



from ■ ■ 

 cause. 



rom t IS after taking them into their bands, could they sometimes be 



made to go. Clock-makers, who may know the principles of 

 their business tolerably well, and who would find no difficulty 

 in making a common eight-day clock to go and perform its 

 office easily, have often been much put to it by month clocks^ 

 They in general have very heavy weights, perhaps th'Krty pounds 

 to the gomg part, and more than that to the striking part; the 

 pendulum balls are very light, little more than one pound 

 weight, if even this^ and vv/ithal have very short arcs of vibra- 

 tion. These circumstances lead me to suspect, that attraction 

 had had a great hand in the stopping of these clocks ; and had 

 this been known then, we should have found the stopping 

 generally to have taken place about the time when the weights 

 had got down, and nearly opposite to the pendulum ball; which 

 is fully confirmed by my examining some old and well-expe- 

 rienced clock-makers on this part of the subject, who said, that 

 this actually was the case, that they always suspected among 

 other causes of stopping, that the weights might have touched 

 the pendulum, and this they very frequently examined, to see if 

 theie was sufficient freedom for the weights to pass the pendu- 

 lum ball without touching it, never dreaming of such a thing 

 as attraction being there ; but this of the weights being oppo- 

 site to the pendulum would not be much noticed, from no sus-^ 

 picion being attached to them, but that of merely touching the 

 pendulum ball. If the influence of attraction (which nov/ 

 riocks have "^"^^ be admitted) takes place in those clocks which have heavy 

 a-ivaiitages weights, it must take place, though in a less degree, in those 

 clocks which go eight days ; and, were it not for the trouble of 



daily 



