DISCOURSE OF W. B. TAYLOR. 259 



relation of magnetic disturbance by an aurora. * An account of 

 these results was communicated by Henry to the Albany Institute, 

 %Tanuary 26, 1832; and was also published in the Report of the 

 Regents of the New York University. A little more than a month 

 later (to wit on March 6, 1832,) he had been able to collate the 

 various published accounts of this aurora ; and he learned " the fact 

 of a disturbance of terrestrial magnetism being observed by Mr. 

 Christie in Engldnd on the same evening, and at nearly the same 

 time the disturbance was witnessed in Albany, and that too in con- 

 nection with the appearance of an aurora." This circumstance led 

 him to make a careful comparison of the notices of auroral displays 

 given in the meteorological reports in the Annals of Philosophy for 

 1830 and 1831, with those of the Reports of the New York 

 Regents for the same period. "By inspecting these two publica- 

 tions it was seen that from April, 1830, to April, 1831, inclusive, 

 the aurora was remarkably frequent and brilliant both in Europe 

 and in this country; and that most of the auroras described in the 

 Annals for this time, particularly the brilliant ones, were seen on 

 the same evening in England and in the State of New York." 

 From which he argues that " these simultaneous appearances of the 

 meteor in Europe and America would therefore seem to warrant the 

 conclusion that the aurora borealis cannot be classed among the 

 ordinary local meteorological phenomena, but that it must be referred 

 to some cause connected with the general physical principles of the 

 globe; and that the more energetic action of this cause (whatever 

 it may be) affects simultaneously a greater portion of the northern 

 hemisphere." f 



In attempting to classify and digest the meteorological data 

 within his reach, Henry became strongly impressed with the 

 necessity of much more extensive, continuous, and systematic obser- 

 vations than any as yet undertaken : and he neglected no oppor- 

 tunities of directing influence upon the minds of our national 



•Professor Hansteen has remarked that "A short time before the aurora 

 borealis appears, the Intensity of the magnetism of the earth Is apt to rise to an un- 

 common height; but so soon as the aurora borealis begins, In proportion as Its force 

 iiitreases, the Intensity of the rriagnetlsm of the earth decreases, recovering Its 

 former strength by degrees, often not till the end of twenty-four hours." (Edinburgh 

 Philosoph. Jour. Jan. 1825, vol. xU. p. 91.) 



t Sllllrnan's Am. Jour.Sci. April, 1832, vol. xxli. pp. 150-155. 



