Collin’s Bone Perforateur Outfit included:  five graduated drills, three forms of burrs and four graduate crown trephines that all fit a universal shaft and handle provided with a geared drive to furnish rapid motion.  The crank handle is attached with a ball and socket joint permitting compact storage.  Trephines are provided with guards so that the degree of cranial penetration may be regulated.  Drills were employed during orthopedic procedures including the union of bone resection.