172 DISEASES OF THE HORSE'S FOOT 



With the special firing-iron (Fig. 86) an indentation, 

 sufficiently large to admit the points of the clamp (Fig. 87), 

 is made on each side of the crack. The clamp is then 

 adjusted, and pressed home tight by means of the sand- 



Fig. 87. — The Sand-crack Forceps and Clamp. 



crack forceps (Fig. 87). According to the length of the 

 crack, one, two, or three clamps may be necessary. 



Another useful clamp, though far more complicated in 

 its structure, is that of Professor McGill (Fig. 88). 



' The object of this invention is to arrange on a spindle, 

 which is screw-threaded at one end with a right-hand 



Fig. 88.— McGill's Sand-crack Clamp. 



thread and at the other with a left-hand thread, two clips 

 or clamps, free to travel on the thread, there being a nut 

 between the two which can be turned by a spanner. The 

 clips are placed on the hoof, one on each side of the sand- 

 crack, the hoof being prepared to receive the instrument 

 by filing a groove or notch for the clamps to fit into, and by 



