178 SCIENTIFIC RECORD FOR 1884. 



in the head of the comet, is very apparent. For a similar reason, in 

 another plate the points observed with the transit-circle from Septem- 

 ber 19 to March 3 are shown. There has rarely, if ever, existed a greater 

 need for precautions of this nature, to assist in the combination of the 

 places oocained at various observatories for the accurate determination 

 of the orbit. {N'ature.) 



. Comets of 1884 : 



Comet 1884 I = Comet (b) 1883. 



= Pons- Brooks's comet. 



= Pous's comet, 1812. 



= 1812 comet. • 

 Comet 1884 II = Comet (&) 1884. 



= Barnard's comet. 

 Comet 1884 (Wolf) = Comet (c) 1884. 



[Comet 1884 Spitaler, May 26.] (Possibly a return of Comet l§o8 III. 



Lost after discovery. No accurate obser- 

 vations obtained.) 

 A new comet of short period. — M. Schulhof, of Paris, has lately ascer- 

 tained that the observations of the third comet of 1858 (a very limited 

 number) are closely represented by an elliptical orbit with a period of 

 about six years and a half. 



Comet c,. 1884. — When the observations of the comet (c, 1884) which 

 was discovered by Herr Wolf at Heidelberg on the 17th of September 

 had been carried on for a few weeks it bee ame apparent that they 

 could no longer be represented by a j^arabola, but that the comet was 

 moving in an eliipse of short period. Its elements have been computed 

 by Professor Kriiger, of Kiel, and by Dr. Zelbr, of Vienna, the former 

 making the period about 2,391, and the latter about 2,470 days ; that is, 

 somewhat more than six years and a half. 



Prof. H. C. Wilson, astronomer in cliarge of the Cincinnati Observa- 

 tory, has issued the seventh publication of the observatory, which con- 

 tains the observations of the comets of 1880, 1881, and 1882, made under 

 the direction of Prof. Ormond Stone until Jj^ine, 1882. Since that time 

 the work has been carried forward by himself. 



Besides the ordinary observations for positions, interesting physical 

 studies of the comets for the three years named are also presented. 

 The method used in reducing and discussing observations of the trains 

 of comets is that of Professor Bredichin, director of the Observatory of 

 Moscow. For reduction to the plane of the orbit formulae found in A. 

 N. Nos. 300 and 1172 were used. This publication also contains ten 

 full-page drawings, showing interesting physical changes in nuclei and 

 tails of h 1881, a and c of 1882. The notes that precede these drawings 

 are instructive, for tl*ey indicate how the new physical theories of 

 Professor Bredichin stand the test in relation to these comets. 



The zodiacal light. — The current volume of the Proceedings of the 



