C 5*4 ] 
one Hand, the inferior Part is elevated above the 
Range of the Teeth, to admit the coming up of the 
Engine, which is to be direded by the other Hand 
being applied to the Winch in any Degree. This 
Engine has its Power fo commanded, that it may be 
ufed without Reftridion, from the molf robuft to 
the mod tender Frame, feeing it ads and exerts its 
Power in proportion to the Refiftance made. Farther, 
as hinted at before, it is enriched with all thofe 
Properties which Authors affirm neceffary to a fuc- 
cefsful Operation ; for this Extenfion, according to* 
their Obfervation, is made deliberately, fteady, 
equally, and in one continued Line, without the 
leaft Variation. And further, in oblique Fradures of 
the Thigh, where the Bones are apt to ride, (and' 
therefore, on that Account, require a continued Ex- 
tenfion in a certain Degree, to prevent the Limbs 
fhortening after the Cure) fuch a Machine muff be 
of excellent Service 5 having the Property of inercaf- 
ing or decreafing the Extenfion at Pleafure, and to 
be perfeded without the leaft Jar or Tremor. 
The neceffary Appendages are Bands, by which 
the Engine extends the Limb; and deferve the fol- 
lowing Obfervations : Immediately from the Axle of 
the great Wheel comes a Girt, at the other End of 
which Girt is a Hook, which links into a Swivel- 
Ring at the Bottom of a Sole-plate : This Sole-plate 
anfwers the Shape of the Foot, and is made of well- 
hammered Brafs, the Infide of which is padded, to 
fit eafy to the Foot: The upper Part hath a Strop fixed 
thereto, which clafps over the upper Part of the Mc- 
tatatfal Bones; and to keep the Strops ending in the 
Sole-plate from galling or prefling the Sides of the 
Foot 
