146 APPENDIX. 



were rendered invisible. Once only was there noticed a connection between cirrous clouds and the 

 aurora. 



" Of the 42 auroras observed during our winter at Port Kennedy (1858— '9) 24 — marked with an 

 asterisk — were in a direction of a space of water, open throughout the winter, or of the vapor rising 

 from it. More than this number might be traced to it, but of these 24 I am certain. On the nights 

 of the 30th and 31st March, 1859, I noticed the aurora between myself and the land; the patches of 

 light could plainly be seen a few feet above the small mass of vapor arising from the water. The 

 opposite land was from two and a half to three miles distant, and I am confident, if this land had been 

 sufficiently high, the most of these 24 auroras would have been seen suspended but a short distance 

 above the surface of the water or ice. Ou five occasions the aurora was observed to cause agitation 

 of the magnectic needle; on one of these, Dec. 24, 1858, I noticed a vibration of 15°; on the other four 

 times the vibration was not much more than a degree; four of these five occurred when the aurora was 

 from south to north, passing through the zenith. A fine wire was attached to the fore yard-arm by 

 insulated supports and led to a snow house with a connection through the floe to the water beneath. 

 Here the gold leaf electroscope was at times applied, and I was enabled to observe the presence of the 

 electricity in the atmosphere and also the influence of the aurora on the instrument. There appeared 

 to occur two periods of minimum electric intensity about 9 P. M. and noon; the instrument not being 

 sufficiently delicate I could not be satisfied about the time of the maximum. On the whole there 

 seemed to be more fur electricity present in the air at Port Kennedy than Baffin's Bay or Davis' Strait. 

 On six occasions in 1857— '8 I observed a well-marked effect on the electroscope by the presence of 

 aurora, the gold leaves diverging with greater force and remaining so for a longer time than usual. 

 On three occasions at Port Kennedy, when the aurora was from horizon to zenith, the electroscope was 

 strongly affected; on all these occasions the electricity was positive." 



[D. W.] 



PUBLISHED BY THE SMITHSONIAN INSTITUTION, 



WASHINGTON CITY, 



MAY, 1862. 



