NATURAL PHILOSOPHY. 129 



chines, or rather induction coils. The objection was, that these induc- 

 tion coils sent their electricity through the cables in sudden intens.'. 

 shocks, which injured the insulation of the cable. In this machine it 

 is apparently a continuous flow, and no spark will jump from one elec- 

 trode to the other, unless first brought in contact, as in batteries. When 

 modified for electro-plating it is much more efficient than the ordinary 

 battery ; for though it deposits the metal more slowly on any one ar- 

 ticle, yet it deposits it much more firmly and Avith a better surface than 

 the ordinary battery does, and it will deposit the same quantity on 

 1,000 articles at once, which enables it to deposit ten times more 

 metal in the same time than its own exciting battery would do. The 

 construction of the machine is apparently very simple, and will not be 

 easily deranged or speedily worn out. 



ANALYSIS OF MAGNETIC STORMS. 



The first analysis of 177 magnetic storms, recently laid before the 

 Royal Society, by the Astronomer Royal, Mr. G. B. Airy, is printed 

 in a late number of the Proceedings of the Society. In regard to 

 the physical inference to be derived from the numerical conclusions ob- 

 tained from tables exhibiting the algebraic sum of fluctuations for 

 each storm, the aggregate or mean for each year, and for seventeen 

 years, the number of irregularities for each year and for the whole 

 period, &c. , Mr. Airy expresses his strong opinion that it is impossi- 

 ble to explain the disturbances by the supposition of definite galvanic 

 currents, or definite magnets, produced in any locality whatever. He 

 suggests that the relations of the forces found from his investigations 

 bear a very close resemblance to what might be expected if we con- 

 ceived a fluid (to which, for facility of language, the name " magnetic 

 ether " is given) in proximity to the earth, to be subject to occasional 

 currents produced by some action, or cessation of action, of the sun, 

 which currents are liable to interruptions or perversions of the same 

 kind as those in air and water. He shows that in air and water the 

 general type of irregular disturbance is traveling circular forms, 

 sometimes with radial currents, but more frequently with tangential 

 currents, sometimes with increase of vertical pressure in the center, 

 but more frequently with decrease of vertical pressure ; and, in con- 

 sidering the phenomena which such traveling forms would present to 

 a being over whom they traveled, he thinks that the magnetic phe- 

 nomena would be in a great measure imitated. Mr. Airy recommends 

 that observations be made at five or six observatories spread over 

 Europe, and would prefer self-registering apparatus, provided that its 

 zeros be duly checked by eye observations, and that the adjustments 

 of the light give sufficient strength to the traces to make them visible 

 in the most violent motions of the magnet. 



CURIOUS MAGNETIC DISTURBANCES. 



At a recent meeting of the Royal Society, Gen. Sabine brought to 

 notice some remarkable magnetic phenomena recently brought to 

 light by his researches, namely, the difference of direction observed in 

 disturbances of the magnetic declination at stations in England, and 

 others beyond the Ural Mountains. The days and hours at which the 

 phenomena occur are, with slight exception, the same, and the move- 



