The crank shaft carries a pinion which gears into a toothed wheel of a coarse pitch, carrying cutters at the ends of the teeth.
245) a rack I, fixed to the carriage, caused a pinion H on the gun to revolve.
The wing of the bird, like that of the insect, is concavo-convex, and more or less twisted upon itself when extended, so that the anterior or thick margin of the pinion presents a different degree of curvature to that of the posterior or thin margin.
In this instance a very slight movement at the root of the pinion, or that end of the lever directed towards the body, 1 is followed by an immense sweep of the extremity of the wing, where its elevating and propelling power is greatest - this arrangement ensuring that the large quantity of air necessary for support and propulsion shall be compressed under the most favourable conditions.
Fixed to the pinion were three cams, for high, low and mean tides.