Electro-Masrnetic Machine. 



■^t) 



within the attracting distance, that is, the distance at which the iron 

 was attracted to the magnet ; by measurement, it was found that the 

 steel magnet attracted the iron one inch and one fourth. A galvanic 

 magnet was next used of the same lifting power, and consequently of 

 much less weight ; the attracting distance of this magnet was found 

 to be one inch and three fourths, shewing a material gain in favor of 

 the galvanic magnet. Mr. Slade inquires, " has Mr. Ritchie's mag- 

 net been so constructed as to give a favorable trial to this principle ?"* 

 Mr. Davenport informs me that each increase in the number of wires 

 has been attended with an increase of power. 



Conclusions. 



1. It appears then, from the facts stated above, that electro-mag- 

 netism is quite adequate to the generation of rotary motion. 



2. That it is not necessary to employ permanent magnets in any 

 part of the construction, and that electro-magnets are far preferable, 

 not only for the moving but for the stationary parts of the machine. 



3. That the power generated by electro-magnetism may be indefi- 

 nitely prolonged, since, for exhausted acids, and corroded metals, 

 fresh acids and batteries, kept always in readiness, may be substituted, 

 even without stopping the movement. 



4. That the power may be increased beyond any limit hitherto 

 attained, and probably beyond any which can be with certainty assign- 

 ed, — since, by increasing all the members of the apparatus, due ref- 

 erence being had to the relative proportionate weight, size, and form 

 of the fixed and movable parts — to the length of the insulated wires 

 and the manner of winding them — and to the proper size and con- 

 struction of the battery, as well as to the nature and strength of the 

 acid or other exciting agent, and the manner of connecting the battery 

 with the machine, it would appear certain, that the power must be 

 increased in some ratio which experience must ascertain. 



5. As electro-magnetism has been experimentally proved to be 

 sufficient to raise and sustain several thousands of pounds, no reason 

 can be discovered why, when the acting surfaces are, by skillful me- 

 chanism, brought as near as possible, without contact, the continued 

 exertion of the power should not generate a continued rotary move- 



* This question I am not able to answer, as I have not seen any account of the 

 apparatus or of the experiment, but on!}' of the result. 



