513 SCIENTIFIC RECORD FOR 18S3. 



ing from an altitude of 45° down to the south and southwest horizon, 

 from which an intense mild light beamed in streaks resembling auroras, 

 while the mass of the cloud exhibited a glow so intense that it was illu- 

 minated as brightly as a whitewashed wall illuminated by a street 

 lamp. This appearance continued until 8p.m., shifting to various parts 

 of the horizon, and demonstrably was not due either to the moon or the 

 reflected lights of the city. Bezold concludes that this was a case of 

 self-illuminated clouds similar to that described once by Sabine. At the 

 same time in the distant Bavarian forest occurred a few peals of thun- 

 der with lightning flashes. [Similar phenomena have been observed in 

 Washington, generally at the end of a period of warm southerly winds 

 when cold westerly winds with light flurries of snow occur. Another 

 form of lightning without thunder has been twice observed by the writer, 

 namely, in Chicago, July 4, 1859, and again in Washington in July, 1874, 

 on both of which occasions the heavens from the zenith to the horizon 

 were for an hour or more brilliant with innumerable simultaneous 

 flashes, stealing with comparative slowness in all directions, apparently 

 on the under surface of a layer of thin, high clouds. No thunder was 

 iieard, nor did any rain fall.] (Z. 0. 0. M., xvir, p. 146.) 



Prof. Adams has studied the magnetic storms of March, 1879, by 

 means of photographic traces at Lisbon, Coimbra, Stonyhurst, Vienna, 

 St. Petersburg, and Bombay, in the northern hemisphere, and Mel- 

 bourne and Mauritius, in the southern. He finds that a diminution of 

 the horizontal intensity occurs with an eastern departure of declination 

 greater at St. Petersburg than at Kew, and vice versa, an increase of 

 horizontal intensity occurs with a west departure greater in St. Peters- 

 burg than in Kew. 



Adams also investigated the much stronger perturbations of August 

 11-14, 1880, by means of the curves from Lisbon, Kew, Vienna, St. Peters- 

 burg, and Toronto. Vienna and Toronto show for hours together strong 

 similarity in their curves and then change to great diversity. The to- 

 tal magnetic intensity at St. Petersburg was changed by nearly one- 

 eighth of its whole value. Any cause that is insufficient to explain the 

 origin of the whole terrestial magnetism could scarcely be considered 

 as sufficient to explain such enormous perturbations. (Z. 0. G. M., xvn, 

 pp. 15, 16.) 



Wild has also expressed his views as to the origin of terrestial mag- 

 netism and magnetic storms in connection with a study of magnetic 

 storms of 1880, August 11-14. From autographic records of Pavlosk, 

 Kew, Zikawei, and Melbourne he concludes: (1) The disturbance of all 

 three elements, declination, horizonal and vertical intensity, began and 

 ended simultaneously. They originated, therefore, from either one single 

 force or from forces that simultaneously began and ended. (2) The 

 individual curves of disturbance at neighboring points, as Kew and 

 Pavlosk, show some similarity, but those of Zikawei and Melbourne 



