Note 133 — Chapter II
Reading edition
As one more conspicuous than any other, it must be stated that, in March 1832, Mr. Bennet Woodcroft patented an “increasing screw-propeller,” which he thus describes: “A spiral worm blade or screw coiled round a shaft (this resembles the invention of Watt) or cylinder of any convenient length and diameter, in such form that the angle of inclination which the worm makes with the axis of the cylinder continually increases, and the pitch or distance between the coils or revolutions of the spiral, continually increases throughout the whole length of the shaft or cylinder upon which the spiral is formed.” (Specifications of “Marine Propulsion,” Part II. p. 112.)