ISO NEW WATCH ESCAPEMENT, 



to the detached escapement in giving the impulse without 

 friction. 



I am, Sir, 



Your very humble servant, 



THOMAS RAMSAY. 



Reference to the Engraving of Mr. S. Mendhams Escape- 

 ment, PL V. Jig. 8, 9, 10, 



Properties of J^ the escapement referred to, there are two principal 

 peculiar properties in the invention, both which I consider 

 superior to any thin^ of the kind laid before the i-iiblic; 

 first, the balance is kept in motion without any frictiori 

 whatever, and in a manner so simple, that even movements 

 of inferior workmanship must go with gveat accuracy. 



Being not in this line of business, or acquainted with any 

 persons in the trade, where I miaht have had an opportu- 

 nity of examining different escapements, I certainly lahour 

 under many disadvantages; for since I have been honoured 

 with the Society's medal, I have heard of an escapement 

 by which the balance is kept in motion without friction, 

 but being limited in the arc of vibration, complicated, and 

 very expensive in the movement, it renders it much inferior 

 to mine. 



The impirise jj^ ^jjg second place, the balance is kept in action by an 

 not given by a. ^ ^ •' 



8troke, impelling power without any blow whatever ; all other es- 



capements, which have fallen within my notice, have kept 

 wp the vibration by a direct blow virtually on the balance 

 itself, which I have always considered to be a great disad- 

 vantage; for a blow upon any thing of the nature of a spring 

 produces that kind of shock, which can by no means be 

 convenient or serviceable in keeping a steady motion, which 

 is so essentially necessary, but is pn the contrary disadvanw 

 tageous. 

 B:»pIanation of The figure, Plate V, fig. 8, represents the escapement 

 without the rest of the train ; a a are the two plates of the 

 frame between which the train runs ; b is the last, or ba- 

 lance wheel of it, with teeth nearly similar to that of the 

 balance wheel of an eight-day clock, moving with the fla(: 

 face of the tooth forward agaipst the pallet e of an upright 



spindle 



