Prelude. A statement or action which precedes the main feature to be presented.
Proximity. Close to; near at hand.
Prototype. That which is used as the sample from, which something is made or judged.
Propeller. The piece of meebanism, with screw shaped blade, designed to be rapidly rotated in order to drive a vessel forwardly. It is claimed by some that the word Impeller would be the more proper term.
Primarily. At the first; the commencement.
Precedes. Goes ahead; forward of all.
Propulsive. The force which gives motion to an object.
Projected. Thrown forward; caused to fly through the air.
Radially. Out from the center; projecting like the spokes of a wheel.
Ratio. The relation of degree, number, amount; one with another.