THE HORSE’S FOOT. 
153 
put on the foot in such a manner that the clip of the heels rests 
against the internal face of the quarters. This done, the space 
between the two heels is measured with a compass, and then the 
dilator is applied (fig. 19). This instrument represents a true 
vice, with jaws reversed, moving from, instead of approaching 
each other. It is formed of two jaws which can be made to ap¬ 
proach or separate by a transverse screw put in motion by a mov¬ 
able lever. The degree of separation is regulated by a graduated 
rule placed horizontally, which serves also to maintain the jaws at 
the same point when separated. The two jaws being introduced 
between the heels of the shoe, the vice being held perpendicularly 
to the plantar face, the screw is slowly turned until the branches 
are opened, say, eight or nine millimetres; then at the point or 
points of the shoe which have yielded to the pressure of the in¬ 
strument, one or more blows are struck with a hammer on the 
outside of the branch of the shoe, to loosen the instrument, until 
