A. MATHEMATICS AND ASTRONOMY. 



MEMOIR BY LE VERRIER. 



Professor Le Vender has presented a memoir to the Acad- 

 emy of Sciences, Paris, upon the superior planets Jupiter, 

 Saturn, Uranus, and Neptune, in which he demonstrates the 

 extent of the motions experienced by each in consequence of 

 the action of the other three. In the work in question he 

 gives the perturbations of Jupiter by Uranus and by Neptune, 

 and those of Saturn by Uranus and Neptune, to be followed 

 by the notice of the perturbations of Uranus produced by 

 Jupiter, Saturn, and Neptune, and another of the perturba- 

 tions of Neptune caused by Jupiter, Saturn, and Uranus. G 

 B, Maij 20, 1872, 1303. 



INFLUENCE OF THE PLANETS ON SUN SPOTS. 



Messrs. De La Rue, Stewart, and Loewy presented to the 

 Royal Society of London the result of investigations made 

 by them on planetary influences upon solar activity, and give 

 as one of several conclusions reached that, in examining the 

 tables for the planets Mercury and Venus, they find in them 

 indications of a behavior of sun spots appearing to have ref- 

 erence to the position of these planets, and which seems to be 

 of the same nature for both. This behavior may be charac- 

 terized as follows : The average size of a spot would appear 

 to attain its maximum on that side of the sun which is turned 

 away from Venus or from Mercury, and to have its minimum 

 in the neighborhood of Venus or of Mercury. 12 A, March 

 28,1872,425. 



VOGEL ON THE SPECTRA OF THE PLANETS. 



Herr Vogel, a director of the private observatory of Von 

 Biilow, near Kiel, who has been making an elaborate series 

 of experiments upon the spectra of various planets, has lately 

 announced some of his results, as follows: The spectrum of 

 Mercury was observed on the 14th of April last, and exhibit- 

 ed the lines C, D, E, b, and F, between which other faint lines 

 were detected. The red part of the spectrum was remarka- 

 bly intense, while the blue and violet were very faint. Venus 

 was observed on the 14th of April, the 15th of June, and the 

 7th of August. The spectrum was throughout bright, clear, 

 and beautiful, so that about thirty lines could be actually 



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