( 8 ? ) 
and 'Divijlon. The upper one is provided firfl with a, 
an oblique Ratchet-Wheel of io Teeth, of what 
Diameter you pleafe, on which, however, depends 
the Length and Breadth of the Syftem itfelf. This 
Wheel has a Stop r, with a depreffing Spring t\ 
Under the Wheel a is a fmaller Wheel b of the 
fame Shape : Both a and b are rivetted together, 
and fixed on a common Axis. Under the Wheel b 
lies a third/, which is a common Tooth-Wheel of 
20 or more Teeth, according as one pleafes : It is 
larger than b , and fmaller than a , turns about the 
fame Axis with the other two above it, and upon it 
is fixed a Stop c, with the Spring d , which catches 
the oblique Teeth of the Wheel b. Immediately 
under this Wheel lies the upper Part of the Opera- 
tor, which may be bell made of Iron or Steel. The ’ 
Wheels may all be of Brafs, except the upper one. 
The Operator is of the fame Thicknefs all over, 
and in its upper Part are fixed as many round Steel 
Pins as there are Teeth in the Wheel f which are 
to catch the Teeth of this Wheel, and move it 
backwards and forwards. The Height of thofe 
Pins ought exactly to anfvver the Thicknefs of the 
Wheel/ The Axis of theW 7 heels a and b is kept 
perpendicularly by the Bridget, which is skrewed 
to the Bottom, as appears by the Figure. The 
Operator gggg moves on the Side, above, and in 
the Middle in two Brafs Grooves / i i and q q ; about 
D it jets out, on which Projection a Piece of Iron h 
muft be well faftened, having a ftrongPin, on which 
the Handle z> fits, as you fee in the SyfiemB B. The 
Side D itfelf Aides in another Groove s s, and in its 
inner Corner joins to it the Determinacor k kk 3 of 
the 
