ANIMAL DENTISTRY. 



137 



vature of their external borders, cannot be conveniently 

 reached with an instrument of any other shape. The angular 

 float should be of the same size and length as the straight 

 one. When its head lies, face downward, upon a plane, the 

 center of the handle should be elevated two and one-half 

 inches above the plane. The short-handled floats of greater 

 angles are much less convenient. 



The Float Blades should be of the rasp variety, tempered 

 hard enough to wear well and yet not so hard as to chip 

 from filing the hard enamel points of the molars. In the 

 straight float the cutting, edges of the rasp must point back- 

 ward, — toward the handle, — and in the angular they must 

 point forward. This arrangement is intended to train the 

 hands to make the float cut on its outward course instead of 

 its inward course, and thereby prevent prodding the back of 

 the mouth. 



Fig. 90. 

 THE FLAT FILE AND RASP. 

 The flat file and rasp should be twelve inches long, 

 rounded at the extremities and have a file on one side and 

 a rasp on the other. It is used to round the first superior 

 and first inferior molars, and to shorten the canines and in- 

 cisors 



THE CLOSED MOLAR-TRIMMER OR CUTTER. 



The closed trimmers are nineteen to twenty inches long, 

 including the handles, and have a head consisting of a box 



