370 ANNUAL OF SCIENTIFIC DISCOVERY. 



there was not much encouragement to prosecute the search, and the 

 planet was not seen in 1860. He, however, remarked that at the next 

 opposition in August, 1861, the planet should appear of the 10 . llth 

 magnitude, or somewhat brighter than in 1857, and he accordingly 

 published an ephemeris to guide astronomers in their search for it. 

 The planet was discovered by M. Goldschmidt, Aug. 27th, 1861. Its 

 observed place differed from the computed place about ten degrees 

 of arc. This error is not very great, when it is considered that the 

 planet's place was computed from an arc of less than four degrees, de- 

 scribed four years previous. It is presumed that Pseudo-Daphne will 

 not again escape from the watchful eye of astronomers ; but Daphne 

 seems entirely lost, and can only be re-discovered by the same sys- 

 tematic search by which it was discovered in 1856. 



Nomenclature of new Planets. At a recent meeting of the 

 French Academy, M. Leverrier brought forward the idea of ceasing 

 to give classical names to the new asteroidal planets, as he consid- 

 ered their number to be necessarily indefinite ; and therefore there 

 must be a limit of classical names. If we must some day change our 

 system, why not begin at once ? Mr. Hind, the English astronomer, 

 however, dissents from this proposal of Leverrier, and at the same 

 time strongly objects to such names as Angelina, or Maximiliana, 

 which, he says, ought to be rejected on the ground of impropriety. 



NEW FAMILIES OF ASTEROIDS. 



In 1859, M. Leverrier presented an interesting paper to the French 

 Academy, on certain irregularities in the motion of the planet Mer- 

 cury. These, carefully studied, led him to the curious conclusion that 

 the planet's motions were disturbed by a quantity of matter revolving 

 between it and the sun. Believing that if this matter had existed in 

 the form of a planet it could not have escaped notice, he concluded 

 that it must be distributed in a group of small bodies, like the aste- 

 roids, circulating between Mars and Jupiter. In confirmation of this 

 idea, he found that Lemonnier, in 1772, saw, under some peculiarly 

 favorable circumstances, a ring or chaplet of small bodies cross the 

 sun's disc, occupying some minutes in doing so. Further researches, 

 submitted to the public during the past year, have enabled him to 

 advance a step farther in the path of discovery thus opened up. 



Leverrier observes that from the action of the planets on each 

 other, their orbits are subject to changes of three kinds. There may 

 be a change in the plane of a planet's orbit, or the angle it forms with 

 the ecliptic ; secondly, in its orientation, or the part of the heavens to 

 which its longer axis points; and, thirdly, in itsybm, or the shape of 

 the ellipse described by the planet. Now, the amount of such changes, 

 ascertained by observation, affords data for computing the masses of 

 the bodies producing them ; and if we assume that the known planets 

 are the only disturbing bodies, it follows that the results obtained 

 the value of the masses should be the same, whatever be the 

 changes from which the computation is made. If the results do not 

 exhibit this harmony, the discordance indicates the action of some 

 body exterior to the planets, which has been overlooked. It was in 

 this way, from the difference between the observed and computed 



