SCIENTIFIC MEMOIRS. 



VOL. II.— PART I. 



Article I. 



Electro-Magnetic Experiments, forming a Sequel to the Memoir 

 on the Application of Electro-Magnetism to the Movement of 

 Machines ; by M. H. Jacobi, Doctor of Science, and Professor 

 at the University of Dorpat*. Second Sei'iesf. 



[From a Pamphlet kindly communicated by tlie Author.] 

 24. 

 X HE question relative to the magnetic power of hollow, soft 

 iron tubes, magnetized by an electrical helix, occupies an im- 

 portant place among the numerous questions presented to us in 

 relation to the employment of the mechanical force of electro- 

 dynamic magnets. A short time previous to my departure from 

 Konigsberg, I had made preparations to undertake a series of 

 experiments on this subject. I was happy to find Professor 

 Parrot engaged in these researches, the important results of 

 which Avill be found published in No. 16 of the Bulletin de 

 VAcademie. This distinguished philosopher had the kindness 

 not only to communicate to me part of these results previous to 

 their publication, but also, at my request, entrusted to me the 

 tubes described in his memoir, in order that I myself might 

 institute similar experiments. These experiments are the sub- 

 ject of the following paper, which 1 have the honour of present- 

 ing to the illustrious Academy, requesting that they will judge 

 of them with indulgence. 



* Translated by Mr. William Francis. 



t The First Series, together with Memoirs by Prof. Botto, Dr. Scluilthess 

 and Prof. Henry, relative to this subject, are to be foimd at p. 503 of the First 

 Volume. 



