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THE MINOR PLANETS.

-end of the year 1880. In 1881 only one was found. It israther remarkable that in the first eight months of 1882 therate of discovery has again increased, nine new ones having beenmet with.* The number discovered in 1879, viz., 20, exceedsthat of any other year; the next greatest being 17 in theyear 1875.

The accurate formation of star-charts, embracing all starsdown to about the twelfth magnitude, has much assisted thoseobservers who, as the above numbers show, have so successfullysearched for these little planets. When in possession of suchassistance, there is still room for the exercise of much skill andperseverance; but, apart from the necessary delicacy of theobservations, all that is requisite is, accurately to compare withthe charts the stars that are seen in any portion of the sky,by means of a powerful telescope, and carefully to noticeany one whose place is not recorded. Then, if the star befound upon a subsequent night to have changed its position,it will follow, that it is not one of those to which the name offixed stars belongs, but that it is really a planet, or (to takethe literal meaning of the word) a wanderer amongst them.By further observation it can next be determined whether it isa Minor Planet that has already been discovered, or a new one.It may be interesting to mention, that those who have per-sistently laboured in such a search find, that they meet withseveral which prove to have been already known, for everyone that is new.

It is worthy of remark that no Minor Planet has ever beendiscovered without the help of a telescope, although it is justpossible to see Vesta (the fourth that was found) with the nakedeye, if it be at its nearest distance from the Earth . At such atime the light received from it does not dilfer much from thatof a sixth magnitude star. Pallas and Ceres are less bright,

* Dr. J. Palisa, now of Vienna , has discovered 8 out of the above-mentioned 9, in the first eight months of 1882 ; the only one in 1881 ;5 out of 8 in 1880 ; and 10 out of 20 in 1879 ; which, with 13 previousdiscoveries, raises his total to 37. This number has, however, been ex-ceeded by Professor C. H. F. Peters, of Clinton (U. S.), who up to theend of 1880 had discovered 41. Other discoverers of 10 or more are asfollows:—Borrelly, 11 {Marseilles)-, Goldschmidt, 14 {Paris and Chatillon)-