I 4 01 ] 
relax the running Knots, the Operation will be long, 
and your Patient will have time enough to cry out. 
In order to avoid thefe Inconvenients, I mounted 
the Bracer on the Lever in a Groove, and I flopped 
it in this State by the Teeth of its elaftic Tail ; by the 
means of this ConftruCtion, when the Surgeon per- 
ceives, that the Bone is over-againft its Cavity, he 
directs the Afiiftant who attends the Extremity of 
the Lever, to prefs upon the Handle (TAB. IV. Fig. i.) 
C D of the elaftic Tail of the Bracer, to the end that 
the Teeth placed under the Arch C, near the faid 
Handle, may quit their Hold, and that the whole 
Bracer, which is now no longer flopped, may flidc 
on the Lever towards the Patient, and by this means 
let the Head of the Bone enter into its Cavity. 
The Neceflity of this Management with our Ambe 
is a Demonftration, that it is far from having that 
capital Fault with which M. ‘Petit reproaches the 
Ambe of Hippocrates : viz. “ That it pufties the 
“ Head of the Bone into its Cavity, before the Ex- 
tenfionand Counter-extenfion are made/' I hope 
the Machines, whereby I have prevented this Fault, 
and have procured to my Ambe the oppofite Per- 
fections, will appear fufficiently Ample. 
If any body Ihould be apprehenfive, that the re- 
entering of the Head of the Bone might be too fudden, 
and occafion a Shock that might hurt the faid Bones, 
it will be eafy to remedy againft it, by fubftituting to 
the Stop, into which catch the Teeth of the Bracer, a 
toothed Wheel A , (Fig. 5. TAB. III.) having in its 
Centre a Handle B t D $ which Handle during the 
Operation will be flopped by the Piece of Iron C, 
fixed upon this Piece by the Skrew F-, the faid Handle 
F f f a will 
