Mr Waddell's Description of a Revolving Paddle Scull. 207 



the stern, and wrought by two men with a crank, or winch 

 handle, attached to the inner end of its spindle or axis. 



The propelling part of the scull was formed of two thin iron 

 plates, each eleven by ten inches in size, producing a surface 

 of 220 inches in whole, which gave a velocity to the boat of 

 four and three-fourth miles per hour. But as the after part 

 of the boat was confined, and the labour in working the scull 

 very great, the men were soon fatigued, and enabled to con- 

 tinue their operations only for a short period. 



This invention of Mr Waddell's promises to be of consider- 

 able utility, and, when operated on by a constant power, to 

 produce great velocity. But to attain the best effect, the 

 scull must revolve from eighty to ninety times in one minute. 

 It may be applied to any vessel, and so placed as to be raised 

 out of the water at a moment's notice, without interfering with 

 the movement of the vessel when under sail. 



In the various experiments Mr Waddell has made on small 

 models of vessels, during the last five or six years, with pro- 

 pelling machines of different descriptions, he has found the re- 

 volving scull to produce the greatest velocity with the least 

 power. In smooth water and light winds, it exceeds the pad- 

 dle-wheels in general use by one-fifth or more ; but in strong 

 head winds, with heavy sea, Mr Waddell is of opinion, that 

 the paddle-wheels would have the advantage. 



This scull might be of great utility in ships of war, when 

 in action, during calms and light winds, by presenting with fa- 

 cility the broadside of the ship towards the enemy ; and for 

 that purpose, might be wrought from a bow or after port- 

 hole on the lower gun-deck, with less than half the number of 

 revolutions stated. 



The boat, with the propelling apparatus, &c, is represent- 

 ed in Plate IV. Fig. 1. 



AA, the boat, which draws about eighteen inches of water. 

 BB, the scull in its proper place when propelling the boat, 

 the spindle or axis of which being an iron rod of about one 

 inch diameter passing through an aperture in the stern-post, 

 and having its inner end fixed to an universal joint connected 

 with rack and pinion work, which operates within board. 



CC, the scull, when not in use, is drawn up through the 

 above mentio n ed aperture, which is elongated for that purpose, 



