TIME KEEPERS, "425 



puflies back the long fpring EF, and unlocks the wheel; and 

 another tooth falling upon the face of the pallet hi gives frefli 

 energy to the balance: and thus the adion is carried on as 

 before. 



The Efcapement fliould be made in the following manner : Inftruaions fiw 

 The pivots of the balance axis au)uld be the fjze of the vergCr ™j'""K ^^^ 

 pivots of a good common fized pocket watch, and of the (hape 

 of i^i^'. 5. PI. XIII, which will greatly add to their ftrenglh, the 

 extreme end, or ading part only bejng ftraight; the jewel 

 hole fliouId be as fliallow as poffible, ^b as not to endanger 

 cutting tlie pivot, and the part of a6iion of the hole made quite 

 back with only a very fliallow chamfer behind to retain the oil; 

 deep holes are very bad, for when the oil becomes glutinous, 

 jt will make the pivots ftick fo as to prevei)t the bali^nce from 

 its ufual vibration. Jhe pallet (bould be half the diameter of 

 the wheel, or a little larger, for if fmaller, the wheel will then 

 have too much adion on jt, which will increafe fridlion moft 

 conGderably, and likewife c^ufe the balance to fwing fo much 

 farther to clear the wheelj confequently a check in the motion 

 of the balance may flop the watch. The face of the pallet 

 Aiould run in a line of equal diftance between the centre of the 

 pallet and its extremity, and not in a right line to its centre, 

 that is an increafe of fri(5lion, ^n4 a lofs of that power which 

 IS obtained by the wheel a6ling on the extremity of the pallet; 

 this is clearly proved by time, by the hole worn by the points 

 of teeth in all pallets that run in a line to the centre. The fcape 

 wheel teeth Oiould form the fame direftion as the face of the 

 pallet, under cut for the faid purpofe of avoiding friflion, and 

 maintaining the power, and for fafe locking. The points of 

 i\\e wheel teeth muft not be rounded off, but left as fharp as 

 poffible, The pivots of the fcape wheel are to be a very little 

 larger than the balance pivots. 



The wheel is locked by a fpring inftead of a detent with Detent with a( 

 pivots, as the French have made them, for thofe pivots muft fp"ng K'"*- . 

 have oil, and when the oil thickens then the fpring of the pivot 

 detents is fo affeaed by it as to prevent the detent from falling 

 into the wheel quick enough, the, confequence of this is ir- 

 regular time and ftoppage of the watch, and if ever fuch 9 

 watch went well for twelve months, chance muft have had by 

 far the raoft hand in it. 



When the fpring is planted on the fide of the wheel, as in How to plac* 



ffiy efcapements, the part oa which the wheel refts Qiould be *^«; *^"^i^» 



pallets, Afc, 

 a little 



