320 POPULAR, LECTURES AND ADDRESSES. 



place of matter falling down from the surface, in 

 consequence of being cooled in the regular regime 

 of solar radiation. It seems, indeed, very im- 

 probable that meteors fall in at any time to the 

 sun in sufficient quantity to produce dynamical 

 disturbances at his surface at all comparable with 

 the gigantic storms actually produced by hot fluid 

 rushing up from below, and spreading out over the 

 sun's surface. 



But now let us consider for a moment the work 

 which must be done at the sun to produce a 

 terrestrial magnetic storm. Take, for example, 

 the magnetic storm of June 25, 1885, f which 

 Adams gives particulars in his paper of June, 1891 

 (Phil. Trans., p. 139 and PI. 9). We find at 

 eleven places, St. Petersburg, Stonyhurst, Wil- 

 helmshaven, Utrecht, Kevv, Vienna, Lisbon, San 

 Fernando, Colaba, Batavia, and Melbourne, the 

 horizontal force increased largely from 2 to 2.10 

 P.M., and fell at all the places from 2.10 to 3 P.M., 

 with some rough ups and clowns in the interval. 

 The storm lasted altogether from about noon to 

 8 P.M. At St. Petersburg, Stonyhurst, and Wil- 



