430 On the Ultra- Violet Spectra of the Elements. [Mar. 15, 



2. During totality I was directed to look for currents in the corona. 

 I can only report a negative result. The structure of the corona 

 appeared in a 4-inch refractor, with a power of 80, to be radial to 

 the limb throughout, and no striking differences in special localities 

 were noticed. 



Appended to the paper are two drawings which do not attempt to 

 give more than the distances to which the coronal rays extended in 

 various directions. One was made by Mr. St. George with an opera 

 glass, and the other by Lieutenant Smith with the naked eye ;. but in 

 the latter case the observer's eyes had been specially covered fifteen 

 minutes before totality, and the brighter portions of the corona 

 were screened from him by a disk of angular diameter three times 

 that of the moon. He consequently traced the rays much further 

 than Mr. St. George, though, allowing for this difference in conditions, 

 the drawings are fairly accordant. 



III. " On the Ultra- Violet Spectra of the Elements. Part III. 

 Cobalt and Nickel." By G, D. Liveing, M.A., F.R.S., 

 Professor of Chemistry, and J. Dewar, M.A., F.R.S., Jack- 

 sonian Professor, University of Cambridge. Received 

 February 27, 1888. 



(Abstract.) 



The authors compare the results obtained by the Rutherfurd 

 grating which they used in measuring the wave-lengths of the iron 

 lines with those obtained with the larger Rowland's grating used for 

 measuring the wave-lengths recorded in this paper, and find them 

 closely concordant. They next compare the measures of wave-lengths 

 of the cadmium lines obtained by them by means of a plane 

 Rowland's grating and a goniometer with an 18-inch graduated 

 circle with those obtained by Bell with a large concave grating of 

 20 feet focal length. The result of the comparison is that the plane 

 grating gives measures which agree very closely with those given by 

 the concave grating, while the former gives more h'ght and is better 

 for complicated spectra, such as those described in this paper, because 

 the overlapping spectra of different orders are not all in focus 

 together as they are when a coocave grating is used. 



The authors give a list of 580 ultra-violet lines of cobalt and 408 

 lines of nickel. They find a certain general resemblance of the two 

 spectra, but no such exact corrrespondence as the close chemical rela- 

 tionship of the two metals would render probable. They point out 

 that the coincidences of lines of the two metals are hardly, if at all, 

 more in number than would have been the case if the distribution of 

 the lines had been fortuitous. They give a map of each spectrum to 

 the same scale as Angstrom's normal solar spectrum. 



