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Medical professionals cut teeth and tissue out of the then-20-year-old’s mouth.

It is not, however, always necessary to cut teeth all round these wheels, as will be seen by an examination of Fig.

It is obvious that rotating cutters of this class cannot be used to cut teeth having the width of the space wider below than it is at the pitch line.

The large gear has cut teeth, and the pinion is of steel, working in gun-metal bearings.

It is not improbable, however, that the contact of tooth upon tooth extends in cast gears across at least two-thirds of the breadth of the tooth, in which case the rules for ascertaining the strength of cut teeth of equal thickness may be employed, substituting 2⁄3rds of the actual tooth breadth as the breadth for the purposes of the calculation.