-&-> mag- 

 was beheld in the 



RECENT MAGNETIC STORMS AND SUN-SPOTS. 165 



17th, and 19th, accompanied by more or less magnetic disturbance. 

 During that time a tremendous sun-spot, exceeding in size the largest 

 of the April spots, was advancing from the edge of the disk to the 

 center. In this country the principal auroral displays were on the 

 nights of the 17th and 19th, and the chief force of the magnetic 

 storm was felt on the 17th. On that day a storm of rain and snow 

 prevailed over most of the Union, and simultaneously with this 

 storm there raged a hurricane of magnetic forces. The effects were 

 similar to those witnessed during the April storm, but more intense. 

 As in April, some wires were worked without batteries, while others 

 could not be worked at all. Cable communication was interrupted. 

 Some startling phenomena occurred. Sparks of fire leaped from the 

 wires and instruments. In the West, switch-boards were burned and 

 keys melted. Operators received 

 severe shocks. Practical tele- 

 graph men said they had never 

 known such a powerful disturb- 

 ance of the magnetic elements. 

 In the evening, when the sky 

 cleared at Chicago, a most 

 nificent sight 



heavens. The brilliancy of the 

 aurora far exceeded that of the 

 April display. A singular feature 

 of this aurora, which was also 

 noticed in Europe, was a splendid 

 luminous arch spanning the sky 

 from east to west and passing 

 nearly through the zenith. An- 

 other feature that added brill- 

 iancy to the spectacle was the 

 variety of color visible. The prevailing tints were rose-color and 

 green, but in some places streamers and patches of violet, yellow, 

 and orange light were seen. On the night of the 19th and morning 

 of the 20th, the sky having cleared here, a splendid aurora was seen 

 in New York. The magnetic disturbance also continued. 



At the April meeting of the American Astronomical Society I ex- 

 hibited some magic-lantern views representing the principal changes 

 which took place in the great sun-spot during the magnetic storm of 

 November. These views, copied from drawings of the spot made at 

 the telescope, are reproduced in the accompanying cuts. 



Fig. 1 represents the spot as it appeared on the 16th of November, 

 the day before the culminating magnetic disturbance took place. Low 

 magnifying powers, varying from sixty -five to a hundred and ten diam- 

 eters, were used while making the drawings, as it was not desired to 

 obtain pictures representing all the details. Consequently, only the 



