C 295 ] 



without the bended fleel fpring, 

 and therefore I did not put it to 

 that which I made ufe of. 



Fig. III. The fmall tube or mea- 

 sure, with the brafs focket, Aider, 

 and fprings, all taken afunder to fee 

 their fhape. The fcrew c under 

 the elaftic piece a\ is to be fixed to 

 the under part of the ihoulder of 

 the brafs focket (at a, in Fig. II.), 

 to fix the elaftic piece a to it. 

 The pin ^fupported by the piece <2, 

 and pafling through a hole in the 

 under part of the ihoulder of the 

 focket, enters a cavity made in the 

 under fide of the brafs ilider, when 

 this Aider is drawn out as in Fig. II. 

 and thus imps its coming out en- 

 tirely. 



U 4 Fig. IV, 



