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SCIENCE. 



[N. S. Vol. XII. No. 292. 



motion many times greater. The distor- 

 tion shown in the iigure indicates that the 

 horizontal motion is very large. 



W. J. Humphreys. Some work has been 

 done by "Wilssing at the Potsdam observa- 

 tory, showing a great change from change 

 of pressure; but he applies this to such 

 stars as Nova Aurigae. He has obtained 

 results, working with hydrogen, showing 

 that the spectrum lines in hydrogen are 

 very sensitive to diminution of pressure. 

 This applies especially to the deeper lines. 

 He has obtained perfectly sharp lines with 

 a pressure of 14 atmospheres. 



Mr. Jewell. From our knowledge of the 

 solar spectrum it is perfectly certain that 

 the lines do not show any evidence of 

 powerful pressure. Under such pressure 

 the lines would probably be broader. 



The Indian Eclipse Photographs of Jan. 22, 

 1898, obtained by the Lick Observatory Ex- 

 pedition : By W. W. Campbell. 

 Photographs of the corona and its spec- 

 trum; and of the spectrum of the sun's edge, 

 were thrown on the screen. Special atten- 

 tion was called to the apparent and proba- 

 ble connection between the prominences 

 and the curved coronal streamers enclosing 

 them and to the relative displacement of 

 the bright and dark lines in the spectrum 

 of the sun's edge. 



Total Solar Eclipse of May 28, 1900. 



Simon Newcomb presented the report of 

 the committee upon the observations of 

 the recent eclipse. 



W. W. Campbell. Being a long distance 

 from our base in California, it was impossi- 

 ble to take our plates home for development, 

 and they were developed in camp, where it 

 was impossible to do photographic work 

 successfully. I have brought one of the 

 original negatives, but Mr. Brown should 

 have the privilege of presenting it. It was 

 taken with an exposure of one second, 

 with a 40-foot camera. It reveals the fact 



that the coronal tails were not so numerous 

 as those in 1898, while those were not so 

 numerous as in 1893. There seems at first 

 to be no connection between the coronal 

 streamers and the prominences ; and yet, 

 if you will go over the plate carefully, I 

 think you will see there is some connection 

 between them. Our spectroscopic material 

 was not so great as we should have liked to 

 obtain ; but for the third contact we ob- 

 tained very satisfactory results. It was a 

 question whether bright lines would be 

 shifted towards the red end, but they seem 

 to show no evidence of such shifting. 



S. J. Brown. The eclipse observations 

 of the Naval Observatory were widely dis- 

 tributed and covered a great deal of ground. 

 Two main stations were occupied, one in 

 North Carolina and the other in Georgia. 

 Our photographic work is not in a condi- 

 tion to exhibit. There was one experi- 

 mental line of research I think it worth 

 while to mention. We wished to try ex- 

 periments with color screens ; and with one 

 lens we used isochromatic plates, and with 

 another lens the ordinary photographic 

 plates, to see whether any indications would 

 be shown as to a difierence of structure of 

 the corona due to the green line. The re- 

 sult showed no difference of structure, but 

 there seems to have been a greater expan- 

 sion of the polar rays when we used the 

 color screens than when we used the ordi- 

 nary plates. Photographs were taken to 

 obtain as great an extension of the corona 

 as possible ; but the sky was not favorable, 

 and we did not obtain so great an extension 

 as was shown by the results in India. The 

 spectroscopic work occupied our most serious 

 attention. We had some very rare grat- 

 ings, ruled to concentrate the light of the 

 first order at a special point. Two of these 

 gratings, from the Johns Hopkins Univer- 

 sity, were utilized, one at Pinehurst and one 

 at Griflin, besides another grating of long 

 focal length. Our preparations for this 



