374 ANNUAL OF SCIENTIFIC DISCOVERY. 



says, " On the approach of the moon to the third satellite (the first 

 occulted), it was perceived that the apparent course of the latter would 

 be nearly parallel with the sloping side of a lunar mountain plainly 

 visible on the outline of the moon's limb, rising by a gentle ascent 

 from the north, and forming on the south the northern limit of a hol- 

 low equal in extent to the apparent diameter of Jupiter, into which, 

 in his turn, he seemed to be plunged. In passing from the summit of 

 the mountain to the bottom of the hollow, the point of its disappear- 

 ance, the third satellite occupied two seconds of time, affording a novel 

 means, in connection with the angle of the mountain's ascent, of de- 

 termining the perpendicular height of the mountain above the general 

 surface of the moon." 



NEW STAR. 



M. GUILLEN Y CALOMARDE has discovered a new telescopic star be- 

 tween the polar star and Cynosure, near the rise of the tail of the Lit- 

 tle Bear ; a star, at least, which did not exist in October, 1849. Ac- 

 cording to the observations of M. Calomarde, the new star should 

 have an increasing brilliancy, and it is likely that, in less than a month, 

 it may be seen with the naked eye. Harper 's Magazine, Nov. 



THE COLORS OF STARS. 



SOME five or six years since, Prof. Sestini, now of the Georgetown 

 (D. C.) College, made in Rome a series of observations on the colors of 

 stars, and he states in the Astronomical Journal that he has lately been 

 engaged in comparing these colors as seen in Rome and in George- 

 town, the same telescope being used in both cases, and to prevent de- 

 ception he has always made the American observations before ascer- 

 taining from his memoir what color was observed in the Italian one. 

 He says : " The results are remarkably uniform ; with a few excep- 

 tions, much more so than I anticipated. So that, were the state of the 

 air to be ranked amongst the causes of the different colors of celes- 

 tial objects, it seems to me that there is but little difference between 

 this atmosphere and that of Italy, even with regard to transpar- 

 ency." This conclusion is founded on various observations of the 

 planets, as well as of the stars. It was, however, the single stars 

 with which this uniformity was observed, for "the double stars were 

 seldom found having the same colors." But besides the double stars, 



O 7 



five out of the four hundred single ones reviewed are noticed as pre- 

 senting remarkable differences. ^' Sagittarii was at Rome deep 

 orange, at Georgetown light yellow ; n Aquilae, deep orange, and 

 yellow ; ^ Serpentis, light yellow, and deep orange ; 6 Pegasi, white, 

 and orange ; y Pegasi, purplish-blue, and white. 



CHANGE IN THE PROPER MOTION OF a VIRGINIS. 



MR. E. SCHUBERT, in a communication to the Astronomical Journal, 

 No. 16, states that, in the course of an entirely new reduction made by 



