204 ELEMENTS OF STATIC ELECTRICITY. 



electric action. The peculiar band and arch formation 

 of cirro-stratus clouds often strongly resembling auroral 

 bands and arches, has, by many observers, been attrib- 

 *ited to similar electric action ; though doubtless occur- 

 ring at a much lower altitude than that of the aurora. 



The existence of strong earth currents during the 

 prevalence of auroras, and of those violent perturba- 

 tions, known as ''electric storms," are well established 

 facts, proved by observations on telegraph lines. Dur- 

 ing the aurora of Feb. 4, 1872, visible over an area 

 embracing 30 of latitude, and 150 of longitude, these 

 currents and perturbations were observed on all the 

 lines within this area, both land and submarine ; being 

 strongest on those having a southeast and northwest 

 direction. 



The following description of the auroral storm of 

 Nov. 17, 1882, is condensed from the Signal Service 

 Reports : " Beginning a little before daylight, it was 

 known at first by its interference with telegraphy. 

 For three hours not a wire of the Western Union Tel- 

 egraph Company could be worked. Late in the after- 

 noon, the trouble seemed to decrease ; and, at night, 

 there was a brilliant aurora prevailing over the eastern 

 half of North America, the Atlantic, and northwestern 

 Europe; and all telegraphic service was interrupted. 

 Cables to Europe, and wires to Chicago, could not be 

 worked; annunciators in telephone offices dropped; 

 the switch-board in Albany, N. Y., was ignited; the 

 switch-board and wires at Chicago were burned ; and an 

 incandescent lamp was illuminated at St. Paul, Minn. 

 A message was sent from Bangor, Me., to North Sid- 

 ney, C. B., 710 miles, by the earth current alone, with- 

 out the batteries ; the current being as strong as that 



