How It Flies; or, The Conquest of the Air / The Story of Man's Endeavors to Fly and of the Inventions by Which He Has Succeeded

by Richard Ferris

U

Uniform Pitch—That varying pitch in a propeller blade which causes each point in the blade to move forward in its own circle the same distance in one revolution.

Up-wind—In a direction opposite to the current of the wind; against the wind; in the teeth of the wind.