INDUSTRIAL PROGRESS DURING THE YEAR 1875. X xv 



As the first-fruits of the labors of the spectroscopic exam- 

 ination of the spectra of transparent substances, Lockyer an- 

 nounces the probable existence in the solar reversing layer 

 of strontium, cadmium, lead, copper, cerium, and potassium. 



The eclipse of the sun of the 6th of April was successfully 

 observed, the photographic observations in Siam being es- 

 pecially successful. It is considered that evidence of high im- 

 portance was obtained bearing upon the general nature of the 

 spectrum of the coronal atmosphere; the tendency being to 

 conclude that the higher regions of the solar envelope differ 

 chemically from the lower regions; the lower portions, in fact, 

 being composed of less complex chemicals at a high temper- 

 ature, while the lower temperature of the upper portions al- 

 lows of the formation of more complex bodies. 



Fuhg has published a discussion of numerous observations 

 of the diameter of the sun, and finds no difference between the 

 polar and equatorial diameters. The views of Father Rosa 

 as to the variable diameter of the sun have been already 

 noticed by us. These views have been lately defended by 

 Secchi, as the editor of the posthumous papers of Father 

 Rosa. 



The Planets. Le Verrier has presented to the Paris Acade- 

 my of Sciences his numerical tables of the movements of Sat- 

 urn. They are based principally upon the observations at 

 Greenwich and Paris. This completes his work for all the 

 bodies of the solar system. 



The measurements obtained by Colonel Tennant by means 

 of Airy's double-image micrometer during the transit of Ve- 

 nus have been subjected by him to some discussion, and he 

 thinks he has a decided indication of the elliptic form of the 

 disk of the planet Venus. 



Dr. Galle has published the results of his discussion of the 

 observations of the asteroid Flora, which were made in con- 

 cert by various observatories for the determination of the 

 solar parallax. His definitive result is 8.87", which agrees 

 very closely with the preliminary results derived by M. Pui- 

 seux from French observations of contact. From the con- 

 course of various methods to its determination, we may be 

 sure that this important element will soon be accurately 

 known. No results for the value of the solar parallax, based 

 on measurements of photographs, have yet been published. 



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