Description of an Electro-motive Engine. \83 



the bent end of the magnets next to the fly-wheel to enable 

 me to work it by a longer rod, which more readily admits of 

 reversing the motion by turning the apparatus at Fig. III. 

 above or below the axle. 



A very short rod would not readily admit of this. Of course 

 a great deal more room would be occupied by placing the fly- 

 wheel opposite to the poles of the magnet. Various modifica- 

 tions however of this, as well as of other parts of the arrange- 

 ment, will readily suggest themselves. But the apparatus 

 at A. B. Fig. I. with its copper bar, binding nuts, and screws, 

 works in so satisfactory a manner, by the motion of the 

 keeper, which it also regulates, that the principle will be 

 found applicable, as I have found it, to a variety of modifica- 

 tions of that described. 



It -is impossible in this country to get apparatus of this 

 description, finished with any thing even approaching the re- 

 quired degree of accuracy. The two electro- magnets des- 

 cribed above, weigh about 80 lbs. each ; yet so defective is 

 their construction, that their lifting power is not one-quar- 

 ter of what it ought to be, or what we find it in those made 

 in England. The iron is common bar iron, and there is but 

 one coil or strand of copper wire used, of about one-tenth 

 of an inch diameter. 



For these reasons, I omit all details of experiments made 

 on the motive power of this arrangement. In fact, such de- 

 tails are unnecessary. All those conversant with the subject 

 will readily be able to form a correct judgment of the prin- 

 ciple on which the movement depends, and the means by 

 which it is produced. It will easily be seen what proportion 

 of the current from the battery or of the induced magnetism, 

 is wasted by any peculiarity in the arrangement. As for 

 the movement itself, it appears to be quite perfect. 



With a view of obtaining a longer stroke, I have tried the 

 magnets and keepers, one over the other, working as one 

 magnet ; but it did not appear that any advantage was ob- 



2 B 



