280 MILLER— SPROUL OBSERVATORY ECLIPSE EXPEDITION. 



cant and seems to me to exhibit the general tendency of coronal 

 streamers to straighten themselves out at some distance from the sun. 



We examined the long streamers on the forty-five second expo- 

 sure with the 62^-foot focal-length camera to see if one would 

 guess from the shapes of the streamers that there was a violently 

 disturbed region immediately below them. Our conclusions were 

 in the negative, that is, that no one would guess from the shape of 

 the outlying streamer that there was any violent agitation at the 

 solar surface. There are many phenomena that lead one to believe 

 that the corona is a magnetic or electric product and it is possible 

 that it results from a combination of these things. At any rate 

 there seem to be abundant reasons to believe that the problem is not 

 beyond solution. 



Dr. L. A. Bauer had consented to give a summary of the mag- 

 netic work done during the eclipse of 1918 at stations under his 

 direction. He was prevented from doing this because of his de- 

 parture to establish stations in Africa and Brazil to make magnetic 

 and electric observations during the eclipse May 29. Before leav- 

 ing he sent a summary of the chief conclusions that he reached from 

 the observations of the eclipse of June 8, 1918. I shall read this 

 summary. 



The following conclusions are drawn covering the chief results of the 

 magnetic observations made in connection with the solar eclipse of June 

 8, 1918: 



(a) Appreciable magnetic effects were observed during the solar eclipse 

 of June 8, 1918, at stations distributed over the entire zone of visibility and 

 immediately outside. (How much further some of the effects may have 

 extended must be left for future study.) The chief characteristics of the 

 effects took place generally in accordance with the local eclipse circumstances 

 and in general accord with effects observed during previous eclipses. The 

 evidences of a direct relation between the magnetic effects and the solar eclipse 

 are so numerous as to warrant drawing the definite conclusion that an appre- 

 ciable variation in the Earth's magnetic field occurs during a solar eclipse. 

 This particular variation is termed here the " solar-eclipse magnetic vari- 

 ation." 



(b) The range of the solar-eclipse magnetic variation, according to the 

 particular magnetic element, is about o.i to 0.2 that caused by the solar- 

 diurnal variation on undisturbed days. The effects are of a more or less 

 complicated character, according to location of observation-station in the 

 zone of visibility. The effects caused during the local eclipse-interval are 

 superposed upon those caused by the continued disturbance of the Earth's 



