ASTRONOMICAL PHENOMENA AND PROGRESS. 



44 



vantageous as regards a clear view of the yel- 

 low line in the solar atmosphere, which M. 

 Rayet has been engaged in studying. An im- 

 perfect image is found a little farther off than 

 the principal focus of the object glass, and from 

 this a determined color is thrown upon the slit 

 of the spectroscope. The author says that the 

 yellow line maybe seen upon the whole cir- 

 cumference of the solar disk quite as easily as 

 the three lines of hydrogen, and infers, there- 

 fore, that the incandescent gas to which the 

 line corresponds is of the same character as 

 hydrogen, one of the constituent elements of 

 the solar system. 



Vapor of Water in the Solar Atmosphere.- 

 Father Secchi, in observing the regions adja- 

 cent to the large solar spots, with a spectro- 

 MODe of high dispersive power, has frequently 

 noticed a series of equidistant nebulous lines, 

 or band.*, in the red and orange. These differ 

 in intensity, and appear to consist of five rays 

 enveloped* in nebulosity, and are seen in the 

 penumbras and the groups of small spots, but 

 usually disappear in the sun's full disk, and are 

 wanting in the interior of the large spots where 

 the rays never have the form of the bands. 

 January 6th, the bands were seen upon the 

 full disk, but were found to arise from a cirrus 

 in front of the telescope, and disappeared with 

 the cirrus itself. Secchi remarked that, un- 

 der these circumstances, the bands due to the 

 neighborhood of the solar spots were sensibly 

 increased in intensity. By studying the re- 

 gion near D of the spectrum with a spectro- 

 scope of nine prisms, he found that the yellow 

 ray of the protuberances really exists in the sun, 

 and may be recognized far from the border. He 

 concludes, from these observations, that the 

 vapor of water exists in the solar atmosphere 

 in the neighborhood of the large spots. 



Solar Activity. During the early part of 

 the year remarkable evidences of activity in 

 the solar atmosphere were noted. At a meet- 

 ing of the Royal Astronomical Society Mr. 

 Bidder and Mr. Browning described two enor- 

 mous spots observed by them. Mr. Huggins, 

 in the discussion that ensued, pointed out 

 the fact that it is only in the neighborhood of 

 the spots that those irregularities of form are 

 to be noticed which have led to the comparison 

 of the granules to willow-leaves, straws, and 

 so on. A cluster of spots measured by Mr. 

 Browning, March 7th, was found to have a 

 length of 97,700 miles, and a breadth of 27,013 

 miles. The direction of its length was as 

 nearly as possible parallel to the solar equator. 

 Toward the close of the year, a group of spots, 

 measuring in its principal dimension about one- 

 eighth of the sun's diameter, was observed. 



Spectra of the Stars. The spectrum of Siri- 

 us has been examined by Father Secchi to de- 

 termine whether there is any displacement of 

 the hydrogen lines due to a proper movement 

 of the star, a question already examined by Mr. 

 Hnjrgins (see ANNUAL CYCLOPAEDIA for 1868). 

 With a four-prism spectroscope the ray F was 



observed to be sensibly displaced, the displace- 

 ment of the centre being apparently equal to 

 the breadth of the rays D' D" of sodium, and 

 being toward the less refrangible side. With 

 a spectroscope of two prisms the displacement 

 of certain of the hydrogen rays, with respect 

 to the rays C and F of Sirius, was also ob- 

 served, and in the same direction. Father 

 Secchi has also examined the spectrum of the 

 variable star R in Gemini, which star attained 

 its maximum brightness with a magnitude of 

 6.5 in February, 1869. The spectrum exhibits 

 a brilliant hydrogen ray, and also luminous 

 bands, of which the principal correspond to 

 dark bands in the spectrum of Alpha Orionis, 

 and is analogous to that of the variable in Co- 

 rona Borealis, which appeared in 1866. Fa- 

 ther Secchi has found in Aldebaran, Alpha 

 Orionis, and Pollux, the yellow ray noticed in 

 the protuberances of the sun, and also in the 

 body of that orb. 



A New Theory of the Universe. Mr. B. A. 

 Proctor has recently proposed a new theory 

 respecting the arrangement of the stars and 

 nebulae. Instead of looking upon the nebulae 

 as for the most part external galaxies of stars, 

 he considers that they belong to our solar sys- 

 tem. He discusses the reasons that have been 

 commonly urged for dissociating the nebulae 

 from our system, and shows that these reasons 

 afford singular evidence in favor of a direct 

 association. He looks upon the stellar system 

 as being far more irregular in its disposition 

 than has been generally supposed, and thinks 

 that it is made up of an almost infinite multi- 

 plicity of streams, branches, and clusters ; here 

 scattered dispersed!^, there more or less aggre- 

 gated ; at one place interlacing, and elsewhere, 

 in the language of Sir John Herschel, " bus- 

 tling upward from the t general level." The 

 Magellanic clouds he looks upon as simply 

 globular aggregations of the sidereal and nebu- 

 lar components which are elsewhere found 

 apart, but which everywhere form but one 

 scheme. The Popular Science Review, com- 

 menting on this theory, remarks that, accord- 

 ing to these views, we see few| if any external 

 universes, though our belief in the existence 

 of multitudes of them is in no way affected. 

 On the other hand, our conceptions of the scale 

 on which our own galaxy is constructed, of the 

 grandeur of its plan, and of the immense va- 

 riety in the forms of matter which compose it, 

 seem to be considerably enhanced by the views 

 put forth by Mr. Proctor. 



The Nebular Hypothesis. Mr. J. S. Aldis, 

 in a contribution to the Philosophical Maga r 

 zine, remarks that a peculiarity in the structure 

 of the earth is worth noting in connection with 

 the nebular hypothesis. There is a tendency 

 in mountain-chains to run north and south, 

 and to present steep slopes to the west, but 

 gentle declivities to the east. This, he sug- 

 gests, may arise from the contraction of the 

 earth. If a portion of the unsupported crust 

 sinks toward the centre, it will subside on to 



