ANNUAL RECOKD OF SCIENCE AND INDUSTRY. 



latter were surrounded by a transparent atmosphere laden 

 with clouds." 



Dr. Meyer, in the V. J. S. of the Philosophical Society of 

 Zurich, has an interesting resume of the history of the dis- 

 covery of JS r eptu?ie, which is one of the best of the shorter 

 accounts of this discovery; and in No. 37 of the Astrono- 

 mischi Mittlieilungen he gives a brief but excellent sketch 

 of the history of double stars, together with a series of 

 measures and an investigation of the orbit of 2 634. 



The AstronomiscJie NachHchten also contains an account 

 by Galle of the discovery of. Neptune. 



Peters, of Clinton, notes a striking similarity between the 

 orbits of Gerda (122) and Urdu (167), their elements being 

 alike except in one point. They move in one orbit about 

 the sun, in the same periodic time, but are about 180 apart. 



In the Smithsonian Report for 1876 Kirkwood has a sta- 

 tistical paper on the asteroids, in which the distribution of 

 their perihelia, etc., is considered, and the analogies of the 

 elements of their orbits are noted, and the same subject has 

 been considered by Luther. 



In a note by the veteran observer of asteroids, Luther, it 

 appears that in the last twenty-nine years he has made no 

 less than 819 observations of 9S asteroids! 



Mr. Stockwell, of Cleveland, in studying the orbit of the 

 asteroid Gerda^ which has been observed in 1872, 1873, 1874, 

 1876, and 1877, "finds that the ensemble of the observations 

 leads to corrections to the elements which are quite inad- 

 missible. The omission of the observations of 1873 leads to 

 elements which almost perfectly represent the observations 

 of 1872, 1876, 1877, but leave residuals of 27' (a) and 9' (t) 

 for L873. Using the 1873 observations alone, elements are 

 obtained which satisfy them within less than 1" in both co- 

 ordinates. The two sets of elements are closely alike in four 

 elements, but the major axes make an angle of 5 or more. 

 Ii is probable, according to Mr. Stockwell, that the planet of 

 1873 was not Gerda. 



We have had to record the rediscovery of Mala (66), and 

 by a similar process Camilla (107) has also been found. 

 Schulhof prepared an ephemeris from January 8 to Febru- 

 ary 25 from the various systems of elements heretofore de- 

 termined. That the uncertainty of this was enormous may 



