I might have this wrong.. there is no real description in the page or references but a 'goose foot' paddle sounds like the shaft going vertically down through the hull & driven directly by the horse(s). With a screw propeller the shaft it is in-line with the boat. The vanes on the (now underwater) paddlewheels hing and flap so they are low drag moving against the direction of travel, but hinged down and high resistance moving in the direction of travel.. Nothing like how a screw propeller operates, overcomplex, unreliable, and not easy to reverse. Horse and ox driven paddlewheelers were common by that period I believe, so this is a logical, if doomed, development. But only doomed in the short term, modern tugs often use a similar form of drive, the Voith Schneider Propeller. Maybe this idea was just too advanced for the materials of the day. EasyTarget (talk) 11:46, 16 December 2011 (UTC)Reply
- The sources indicate a screw similiar to Ericsson’s propeller. This source says “Grieve and another Providence man, John Nichols (Jonathan Nichols, a blacksmith from Vermont. ed.), conceived the plan of propelling vessels by the use of screws, or by what is now called Ericsson’s propeller. The Bishop source says: David Grieve ... to propel a vessel by means of screws moved by horse power. Rhode Island Society for the Encouragement of Domestic Industry (1859) says On the other end of each of these shafts was a screw about three feet in diameter. --Doug Coldwell talk 12:47, 16 December 2011 (UTC)Reply