534- DR. SCIIULTHESS ON THE APPLICATION OP 



of substituting for tlie cylindrical form the ordinary U fonn of electro- 

 magnetic bars, and of augmenting within certain limits the number and 

 magnitude of these pieces, as well as the length of the spirals. 



But not ImAdng arrived at the termination of my experiments on this 

 subject, I confine myself for the present to pointing out the above-men- 

 tioned facts, which I have thought proper to make known, not only as 

 interesting to science, but also because the study of the new class of 

 effects with which it is connected may be considered as fertile in useful 

 consequences in a physico-mechanical point of view*. 



Part of a Lecture on Electro- Magnetism, delivered to the 

 Philosophical Society at Zurich, February the \Sth, 1833; 

 by the late Dr. K. ScHULXHESsf. 



From a work intitled " Ueber Electromagnetismns, nebst Angabe einer neuen 

 durch electromagnetische Kriifte bewegten Mascliine : Drey Vorlesinigen 

 von Dr. R. Schulthess. Zurich, 1835." 



X HOUGH electro-magnetism from its intrinsic importance certainly 

 is one of the most remarkable and interesting discoveries of modern 

 times, yet it would create a much higher interest, and gain in popula- 

 rity, if it could be rendered practically useful. For some time past I 

 had been occupied with the idea, whether the power of electro-magnets, 

 Avhich without doubt might be infinitely increased, could be applied as 

 a motive power for machinery. It was known from Van Moll's experi- 

 ments, that when the electric current which runs through the spiral of 

 an electro-magnet is rapidly reversed, the magnetic poles are likewise 

 instantly reversed ; and that a light iron keeper, which is supported from 

 its poles, falls oif at that moment, but is immediately re-attracted. The 

 experiments of Henry and Ten Eyck showed that the power of such 

 electro-magnets might be very greatly augmented. The thought struck 

 me, that a considerably heavier keeper or armature might be suspended 

 from such an electro-magnet, and that by the attraction and repulsion 

 of the same a machine might be put in motion ; at the same time the 

 action of the gyrotrope, and thereby the reversion of the poles, might 

 also be effected : and although the distance which the keeper would 

 recede from the magnet could be but very inconsiderable, still I thought 

 that the rapidity with which these motions would follow each other 

 might in great measure compensate for this defect. I was, however, 



* The appai-atus mentioned in this Note was constructed by M. Jast, me- 

 chanicicin of the Royal University of Turin, who executes with the same success 

 and the same accuracy all other kinds of philosophical instruments. 



t The translation has been communicated by E. Solly, jun., Esq. 



