1833,] 



Electro-Magnetic Motors. 



181 



November 1833 5 vol. xxvi. p. 397= observation in November, 

 1835; vol. XXIX. p. 390. Letter from the Rev. W. B. Clarke, de- 

 mjing the alleged periodicity ; vol. xxx. p. 369. A more recent paper 

 by Prof. Olmsted, has been reprinted by Prof. Jameson, in his Nevy 

 Edinburgh Phil. Journal for July last. Prof. Olmsted's first paper 

 contains an extensive collection of observations of the Meteors of Nov. 

 13, 1833, made in different parts of the United States, and gives various 

 inductions from them. In it also is proposed a theory to explain the 

 phfEnomena, which is thus finally expressed : — " That the Meteors of 

 JVov. \3th consisted of portions of the extreme parts of a nebulous body, 

 which revolves around the sun in an orbit interior to thai of the earth, 

 hut little inclined to the plane of the ecliptic, having its aphelion near 

 to the earth^s path, and having a periodic time of 182 days nearly^'' — 

 Silliman's Journal, vol. xxvi. p. 172. 



Some observations on shooting stars, made at Devonport in Novem^ 

 ber, 1836, have been noticed in our last volume, p. 234. Observa- 

 tions of the same period, made at Berlin, Breslau, Frankfort-on-the- 

 Maine, and Gummersbach, will be found in Poggendorf s Annalen^ 

 vol. xxxix. p. 353—356. 



The frequent appearance of shooting stars in August had been no- 

 ticed in England b)^ Dr. T. Forster (see Phil. Mag., First Series, voL 

 Ixiv. p. 294), and at Pavia, we believe, by M. Bellani.~E. W. B.]— 

 Philosophical Magazine, Sfc. 



3. — Electro-magnetic Motors. 



[This strange and unlooked-for application of Magnetism is now 

 engrossing a large share of attention among scientific men. In the 

 4th part of the Scientific Memoirs are a series of papers on this most 

 curious subject, by Professors Jacobi and Bioto and Dr. Schulthess, 

 of the continent of Europe, and Professor Henry of the United States. 

 Professor O'Shaughnessy of the Medical College at Calcutta, has also 

 put together a model of a machine propelled by this mystic power. 

 Professor Jacobi is sanguine " that the superiority of this new motor, 

 with regard to the absence of danger, the simplicity of the applica- 

 tion, and the expense of the materials necessary to keep it in action, 

 is placed beyond doubt." Professor O'Shaughnessy is more confident 

 still in his favorable predications : he says, " I am myself sanguine as 

 to the result; and though 1 feel that full success in the attempt is 

 beyond my capacity and resources, I confidently expect to see, ere long, 



