W. T. Brigliam — Recent Eruption of Kilauea. 507 



observed lines of force surrounding the sphere. That there 

 might be no doubt about my own position on the subject, I 

 arrived at the formula for the lines of force by the geometrical 

 and also by the harmonic analysis, never imagining that a 

 critic would convert this common mathematical process into a 

 physical reality of the sun's constitution. We are now 

 interested to discover an analytical expression for the curvature 

 of the coronal streamers; their physical nature is another ques- 

 tion, one which is at present beyond our knowledge ; it shares 

 the perplexity attending any discussion of electrical or mag- 

 netic action. This then is the second irrelevant criticism. I 

 did not suppose that the cosine distribution of electricity was 

 actually plastered over the surface of the sun, and there was 

 no need to allude to this point. Professor Nipher quotes me 

 as saying, "on the supposition that we see a phenomenon 

 similar to that of free electricity," (p. 21.) If the presence 

 of the word "similar" was not sufficiently explicit as to my 

 meaning, he should have quoted from page 19 of my paper as 

 follows: u We have avoided speaking of the apparent coronal 

 structure as a phenomenon of electricity, in deference to the 

 doubt that free electricity can exist at such high temperatures 

 on the sun's surface, but have shown that some force is present 

 acting upon the corona according to the laws of electric poten- 

 tial." No one can at present explain the physical constitution 

 of the matter that produces the coronal streamers, but 1 have 

 in my work endeavored to show that they coincide in direction 

 with stream lines produced by matter obeying the Law of the 

 Newtonian Potential Function in the case of Repulsion. Such 

 evidence as has been acquired to exhibit this identity of form 

 between the coronal lines and the theoretical lines is now being 

 published. [Proc. A. S. P., No. 16 or No. 17, and this Journal, 

 July, 1891.] 



Washington, April 29, 1891. 



Art. LXII. — On the recent Eruption of Kilauea • by W. T. 



Brigham.* 



I present herewith my report on the changes that have 

 taken place in the crater of Kilauea during the past month. 



The last week of February, I found the crater in a state of 

 intense but not extensive activity. During the seven months 

 that had elapsed since my last visit, the depressed area of 1885 

 had been filled to a height of nearly 150 feet, and there were 



* Report to Prof. Wm, D. Alexander, Surveyor General, dated Honolulu, H. I., 

 April 8th, 1891. 



