a person or thing that propels; specif., a device (in full screw propeller) on a ship or aircraft, consisting typically of two or more blades twisted to describe a helical path as they rotate with the hub in which they are mounted, and serving to propel the craft by the backward thrust of air or water
The motive power was india-rubber in the condition of torsion; the propeller, a screw.
Later apparatus, such as Pettersson's bifilar current-meter or his more recent electric-photographic apparatus, and Nansen and Ekman's propeller current-meter, measure both the direction and the velocity at any moderate depth from an anchored vessel.
In 1833 his caloric engine was made public. In 1836 he took out a patent for a screw-propeller, and though the priority of his invention could not be maintained, he was afterwards awarded a one-fifth share of the £20,000 given by the Admiralty for it.
Sigsbee's small water-bottle on the double valve principle actuated by a propeller requires extremely skilful handling to enable it to give good results.
The "Thetis" propeller fouled a net laid at the entrance to the harbour and carried it with her.