Kew ftleiit Efcapement for Clods. 343 



made to aS againfl the fprings E E, ferve to adjuft them to a proper diftance and degree of 

 ftrength; and by that means eafily to put the pendulum in proper beat. In fig. i, the pen- 

 dulum is partly reprefented by doued lines, in order to fliew the crank, &c. 



The advantages of this efcapement are, 1 ft, fimplici ty of conltrudion ; and confequently cheap- 

 nefs. It can eafily be adopted by the manufacturers of the common wooden Dutch clocks, as 

 the whole efcapement can be formed of a few pieces of wire bent till properly adjufted, with- 

 out even the neceflity of the adjufting fcrews 1 1. Therefore the benefits of this invention 

 may extend even to the poorer part of the public. 



adiy. Total filencc when going : clocks being excluded by many perfons to whom and 

 from many places where ufcful, upon account of their noife. 



3d!y, Keeping good time, arifing from this principle, that the crank always impels the pen- 

 dulum in the fame manner ; that is, as it pafles through the femicircle under its centre always 

 one way; and as it paffes through the femicircle oyer its centre always the other way ; and it 

 recurs in the fame fituation itfetout from, after thefe two impulfes; which being eafily made 

 equal by means of the adjufting- fcrews, notwithftanding the fmall difference in length of the 

 levers adted upon, all the fucceeding impulfes mutl alfo correfpond with thefe, and be equal 

 and regular, as far as regards the efcapement itfelf. In other efcapements, if any irregularity 

 exifts, or is worn in any one or more of the teeth or pins in the fcape-whccl and the pallets, or 

 inclined planes they aft againft, the impulfe given to the pendulum cannot be equal and re- 

 gular; and the higher the number of the fcape-wheel, the greater this chance of imperfeftion. 



4thly, Durability and great certainty of continuance. This efcapement does not require 

 oil ; which, as it becomes clammy and thick by the duft, is the frequent and well-known 

 caufe of the ftopping of others : it does not wear itfelf untrue and out of order. The fric- 

 tion of the collets upon the crank muft be very fmall, as the afting furface is fmall ; and 

 as the intenfity of the impulfe upon the pendulum is in proportion lefs in this, as it a<5ls upon 

 a longer l«ver than in others j alfo< at the time that the chief force is exerted, as the crank 

 pafles over and under its centre, there is very little turning of the collets upon it : fo that 

 I judge this efcapement, properly made, ftands a fair chance of lafting as long as the train it- 

 felf, without being out of order; which I underftand is far from being the ftate of others. 



The ingenious part of the public can no doubt improve upon this application. Of the va- 

 rious methods I have tried, this appears to me to be the beft^ for general ufc. I can fend the 

 Society drawings * of the other methods which I have tried, if by this they (hould judge 

 them worthy their notice. In the one, the crank, befides its own, can be applied with all 

 the advantages of a dead beat ; and in the other, of a detached'efcapement: but they will not 

 have the advantage of filence. v 



I was induced to apply this motion to a ready-made clock, in order to try, by the fame 

 machine, a point of which I had fome doubt; namely, that perhaps, on account of the greater 

 velocity of the afting part, this method might require more power than the common. The 



• The drawings here alluded to, a»alfo a model of wiothcr efckpcmcac bjr Mr. Goodrich, are refer»ed io 



the Seciety'i colUaioiu 



Y y 2 experiment 



