54 APPENDIX. 



In river navigation, where there does not exist the necessity of deeply immersing the wheels, 

 and the common paddles can be made much broader without inconvenience, the advantages of 

 this construction will not be so much felt : at the same time, it may always be employed 

 beneficially, and will occasion less lost power than the common wheel. 



ADDITIONAL EXPERIMENTS ON PADDLE WHEELS. 



The results of the preceding investigations have been fully borne out by a very interesting 

 and complete set of experiments made by Mr. Field, (most of which I attended,) with the 

 view of comparing the effect of the cycloidal and Morgan's wheel with the common one, with 

 different proportions, number, and arrangements of paddles. 



The apparatus, by which the experiments were made, consisted of a vertical shaft, which 

 was hung so as to revolve freely in the centre of a circular reservoir. The wheel was 

 suspended in a horizontal arm attached to this shaft, and was put in motion by a descending 

 weight, which caused the wheel to revolve and carry the horizontal arm, with a small plate 

 attached to it to represent the resistance or vessel, round the reservoir. The weight was 

 wound up to the same height at each experiment, to cause the wheel to make an equal 

 number of revolutions ; and the time employed by the weight in descending, and the number 

 of circuits made, were accurately observed. The different states of immersion of the wheel 

 were produced by altering the level of the water in the reservoir. The column describing 

 the effect is calculated by multiplying the square of the velocity by the number of circuits 

 and the area of resistance. 



