[ 10 4 ] 
F is the pivot or gudgeon. 
c c is the fedtion of an hollow cylinder of wood, 
the diameter of the interior part being fome- 
what larger than the cylindrical ferrule B. 
a a is the fedtion of a ferrule of brafs, driven into 
the end of the hollow cylinder, and which is 
adj lifted to that marked B, fo as to Aide freely 
thereupon, but with as little Shake as poftible. 
bb y dd, gg, reprefent the fedlion of a brafs ferrule, 
plate, and focket, fixed upon the other end of 
the hollow cylinder j the focket dd being ad- 
justed to Aide freely upon the cylinder E, in the 
fame manner as the ferrule a a Aides upon the 
cylinder B : the outer end of the focket at 
gg is formed into a fort of button; by pufhing 
whereof, the hollow cylinder will move back- 
wards and forwards, or turn round at pleafure 
upon the cylindrical parts of the axis B and E. 
e e, i i, o o , reprefent the fedtion of a brafs ferrule, al- 
fo Axed upon the hollow cylinder : the edge of 
this ferrule 
ee is cut into teeth, in the manner of a contrate 
wheel ; and the edge thereof 
o o is cut in the manner of a ratchett. 
Of confequence, when the plate b d db is 
pufhed clofe to the ferrule D, the teeth of the 
ferrule e e will lay hold of 
G, a pin Axed into the axis; by which means the 
hollow cylinder is made to turn along with the 
wheel and axis : but being drawn back by the 
button gg, the hollow cylinder is thereby dis- 
engaged from the pin G, and ceafes turning. 
Note. The weight in the l'cale is prevented 
from 
