250 TRANSACTIONS OF THE [MAY 17, 



channels, some of them more than a thousand miles in lengtli, 

 with a pretty uniform width of fifty or sixty miles; and from his 

 observations he constructed a new maji, dilfering from the older 

 ones somewhat seriously, though still accordant in the most 

 essential features. His nomenclature of the seas and continents 

 derived from ancient geography is certainly a great improvement 

 on that of his predecessors, who had affixed to them the names 

 of their friends and acquaintances among living astronomers. 

 There has been some scepticism as to the reality of these 

 *' canals;" but in 1879 and 1881 they were all recovered by 

 Schiaparelli, and several other observers, notably Burton, also 

 made tliem out. Moreover, Terby finds from drawings in his 

 possession that they had before been seen, though not under- 

 stood or clearly recognized, by Dawes, Secchi, and other ob- 

 servers. At ]H'esent, the balance of evidence is certainly in their 

 favor, especially as the observers at Nice report seeing them last 

 spring. I do not think the same can be said in respect to 

 another observation of Schiaparelli's on the same object made 

 in 1881. He then found nearly all of these canals — more than 

 twenty of them — to be double, i. e., in place of a single canal 

 there were two — parallel and two or three hundred miles 

 apart. No one else so far has confirmed this "gemination" of 

 the canals; but the planet does not come to a really favorable 

 opposition again until 1890 and 1892, when probably the ques- 

 tion can be settled. 



The time of rotation has during the past year been determined 

 with great accuracy by Bakhuyzen, who has corrected some 

 errors of Kaiser and Proctor, and finds it 24'' 37'" 22.6G«. 

 In 1876, there still remained some question as to the amount by 

 which the planet is flattened at the poles. The majority of ob- 

 servers had found a difference between equatorial and polar 

 diameters amounting to between y/jy- and -^V? while, on the other 

 hand, a few of the best observers had found it insensible. The 

 writer in 1879 made a very careful determination, and found it 

 ■jH' ^ quantity closely agreeing with the theoretical value de- 

 duced by Adams as probable from the motion of the newly-dis- 

 covered satellites. 



The Asteroids. 



On May 1st, 1876, the number of known asteroids was 163. 

 To-day it stands at 258, 95 of these little bodies having been dis- 

 covered within the decade, 45 of them by one man, Palisa, of 

 Vienna, while our own Peters is responsible for 20. 



None of the new ones are especially remarkable, /. e., some of 

 the older ones are always more so; the most inclined and most 

 eccentric orbits, the longest and the shortest periods, none of 



