330 ANNUAL OF SCIENTIFIC DISCOVEEY. 



ness of the Sun would in its condition at that time have tended more 

 powerfully than in its subsequent or present state to keep the planets 

 near the plane of its equator. The discovery of this law regulating 

 the inclinations of the planetary orbits appeared to him another addi- 

 tion to the class of facts which establish the analogy between the solar 

 system and that of Jupiter and his satellites, it being well known to 

 astronomers that the inclination of the orbits of the latter to the plane 

 of Jupiter's equator was a function of their distances and masses. 



ASTRONOMICAL OBSERVATIONS WITH THE SPECTROSCOPE. 



Mr. Lewis M. Rutherford, of New York city, communicates to 

 Silliman's Journal the results of some analyses of the spectra afforded 

 by the light of several of the planets and of the fixed stars, of which 

 we give the following summary: "The Sun's lines generally find 

 their counterpart in the lunar spectrums. In the spectrum of Jupiter 

 are found two bands in the red and orange which are not found in 

 the solar spectrum. It may be that these are absorption bands, due to the 

 action of the atmosphere of the planet, and the application of suffi- 

 cient optical power may resolve them into lines. 



"The star-spectra present such varieties," says Mr. R., "that it is 

 difficult to point out any mode of classification. For the present I 

 divide them into three groups : first, those having many lines and 

 bands and most nearly resembling the Sun, viz., Capella, /3 Geminorum, 

 a Orionis, Aldebaran, y Leonis, Arctnrus, and ft Pegasi. These are 

 all reddish or golden stars. The second group, of which Sirius is the 

 type, present spectra wholly unlike that of the Sun, and are white 

 stars. The third group, comprising a Virginis, Rigel, etc., are also 

 white stars, but show no lines : perhaps they contain no mineral sub- 

 stance, or are incandescent without flame. 



" It is not my intention to hazard any conjectures based upon the 

 foregoing observations ; this is more properly the province of the chem- 

 ist ; and a great accumulation of accurate data should be obtained 

 before making the daring attempt to proclaim any of the constituent 

 elements of the stars. 



" One thought I cannot forbear suggesting : we have long known 



^j <_ fj <Z7 <_J 



that ' one star differeth from another star in glory ; ' we have now the 

 strongest evidence that they also differ in constituent materials, 

 some of them perhaps having no elements to be found in some 

 other. What then becomes of that homogeneity of original diffuse 

 matter which is almost a logical necessity of the nebular hypothesis?" 



NEW ASTRONOMICAL HYPOTHESIS. 



A writer in one of the late English reviews submits for considera- 

 tion the following astronomical hypothesis : 



" Whether M. Maedler's discovery of a central sun round which our 

 whole solar system is revolving with scarcely conceivable rapidity may 

 not afford an instant explanation of the planetary ellipse ? 



" Every one acquainted with the mere alphabet of astronomy is of 

 course perfectly aware that the ever-memorable problem propounded 

 by Sir Isaac Newton in relation to the planetary orbits expressed itself 

 literally in these ipsissirna verba : 'To determine the nature of the 



