184 



Electro-Magnetic Motors, 



[Jan. 



It is the same machine that has been ah-early described, except that 

 the exterior fixed circle is now composed entirely of electro-magnets. 



The entire apparatus is therefore constructed of soft unmagnetic 

 iron, which, being properly wound with insulate copper-wire, is mag- 

 netized in an instant, by the power of a very small battery. 



The machine is indeed the identical one used before, except that 

 the exterior circle of permanent magnets is removed, and in its place 

 is arranged a circle of soft iron, divided into two portions to form the 

 poles. 



These semicircles are made of hoop-iron, one inch in width, and 

 one-eighth of an inch in thickness. They are wound with copper- 

 wire insulated by cotton— covering about ten inches in length on each 

 semicircle, and returning upon itself by a double winding, so as ta 

 form two layers of wire, making on both semicircles about one thou- 

 sand and five hundred inches. 



The iron was not wound over the entire length of one of the steel 

 semicircles; but both ends were left projecting, and being turned in- 

 ward, were made to conform to the bend of the other part ; each end 

 that is turned inward, and not wound, is about one-third of the length 

 of the semicircle. These semicircles being thus fitted up, so as to be- 

 come, at pleasure, galvanic magnetics, were placed in the same 

 machine that has been already described, and occupied the same place 

 that the permanent steel magnets did before. The conducting wires 

 were so arranged, that the same current that charged the magnets of 

 the motive wheel, charged the stationary ones placed around it, only 

 one battery being used. It should be observed, that the stationary 

 galvanic magnets thus substituted for the permanent steel ones, were 

 only about half the weight of the steel magnets. This modification of 

 the galvanic magnet, is not of course the best form for efficiency; this 

 was used merely to try the principle, and this construction may be 

 superseded by a different and more efficient one. But with this 

 arrangement, and notwithstanding the imperfection of the mechanism 

 of the machine— when the battery, requiring about one quart of dilut- 

 ed acid to immerse it, was attached, it lifted 16 lbs. very rapidly, and 

 when the weight was removed, it performed more than 600 revolu- 

 tions per minute. 



So sensible was the machine to the magnetic power, that the im- 

 mersion of the battery one inch into the acidulated water was sufficient 

 to give it rapid motion, which attained its maximum, when the battery 

 was entirely immersed. It appeared to me that the machine had more 



