5-2 



APPENDIX. 



TABLE III. 



From an examination of the above table, we arrive at several important conclusions. In the 

 first place it is seen that when the wheel is slightly immersed, little or no advantage is gained 

 from the vertically acting paddle, the loss from the additional velocity required to obtain the 

 necessary resistance or receding of the wheel being fully equal to that of oblique action in the 

 common wheel. The only remedy for such an evil is the increase of the number and dimen- 

 sions of the paddles, both of which are difficult to accomplish in Morgan's wheel : we may 

 therefore very fairly conclude, that in the navigation of rivers or smooth water, where generally 

 little variation is required in the degree of immersion of the vessel, the common wheel, if pro- 

 perly proportioned, is preferable to the vertically acting wheel, in consequence of its admitting 

 of a larger surface of paddle board. 



In the case of deep immersion the effect is very different : here the loss from oblique 

 action in the common wheel becomes very serious, so that the total loss of the engine 

 amounts 'to '447 of that expended, while the loss from Morgan's wheel remains nearly 

 the same. It therefore appears, that the latter has great advantages over the common 

 wheel for sea purposes or long voyages, where the immersion of the vessel is constantly 

 diminishing by the exhaustion of the coals and other stores required at the com- 

 mencement of the voyage. The loss from the oblique action of the paddles must also 

 be very great in rough weather, from the degree of immersion to which the wheel is 

 subject; in addition to which, the paddles entering the water with so great a velocity, 

 receive a reaction or blow which has the effect of nearly bringing up the engine, and 

 there in consequence results a loss, in addition to that of oblique action, from the power 

 required to put the mass of machinery again in motion. The advantages which the common 

 wheel possesses in still water, of presenting a larger surface of paddle board, does not now 

 exist, as a large surface has a tendency to bring up the engine, and throw all the work on the 

 oblique paddle, which is in every case disadvantageous. In fact, the desideratum that has to 

 be aimed at in every wheel, is to throw as much work as possible on the vertical paddles, 

 where there is no loss from oblique action, which can be accomplished in the ordinary con- 

 struction when the immersion does not exceed one-fourth of the radius, and a large surface of 

 paddle board taken advantage of; but at sea it can only be effected by reducing the number 



