( S 4 ) 
the fame Thicknefs with the Operator, the Shape 
of which is fufficiently exprefled in the Figure. 
This Aides alfo up and down, on the one Side in 
the Groove s s, and v on the other Side, where it is 
fmalleft, in a fmall Piece of Brafs %, and where it 
is broadeA, above in the Operator itfelf* which is 
either hollowed out into another Groove, or filed 
off obliquely. The Aiding Part of the Determina- 
tor ought afterwards alfo to be fitted to it. Its 
chief Part is the Lock (landing perpendicular on 
irs broad Part. I have drawn it leparately in Fig. 4. 
B B, in which tffie Aiding Stop c y which is prefied 
down by its Spring d , but raifed by the Tricker aa. 
That Tricker has a Pin b , on which is skrewed on 
the fmall Handle 1 1 (Fig* 1. in the Syftems BB and 
CC.) In the Brafs Bottom A A (or act Fig. 1.) you 
muft file out 10 Ratchet-Teeth or Kerfs, purpofely 
for the Stop of this Lock, or, which is better, you 
may infert into the Brafs Bottom a fmall Piece of Iron 
filed out according to this Figure. The Partition 
and Length of thefe Rachet-Teeth in the Bottom 
muft fit exa&ly with the Circumference of the 
Wheel/, (Fig. 1. Syftem A A,) with this Direction, 
that if the Lock is kept by the uppermoft Tooth 
in the Bottom, the Operator cannot be moved at 
all ; but when by prefting down the Tricker a a, 
( Fig. 4 ) the Determinator is flioved down, and is 
flopp’d by the fecond or third Tooth in the Bottom, 
the Operator being alfo drawn down as far as the 
Determinator permits, makes the Stop c ( Fig. 1. 
Syfl. A A) Aide over ion Teeth of the fecond 
Wheel b ; confequently the fame Stop c, muft Aide 
over 9 Teeth, when the Lock of the Determinator 
will 
