134 RECORD OF SCIENCE FOR 1887 AND 1888. 



Hilsingfors-Gotha, C5°-55°. — Catalogue fiuisLod to the precessious; 0^ ready for 



l)rc.ss. 

 Camhrid{/e (Harvard), GS'^-feOo. — Reductions uearly completed. 

 Bonn, 5O'-^-40°. — Reductious well advanced. 

 Lund, 400-35°.— Two-thirds reduced to 1875.0. 



Leidin, 35^-30°. — Zones printed, and precessions for catalogue partly finished. 

 Camhridge (England), 30°-25°. — Observations nearly complete; reductions proceeding 



rapidly. 

 Berlin, 25°-30°. — Reductions nearly finished. 

 Berlin, 20°-15°. — Reductious under way. 

 Leipzig, 1.50-5°. — Observations practically finished. 

 Alharry, 5°-]°. — In press. 

 Nicolaicf, -\-\° . . . —2°. — Observations finished; reductions progressing. 



Observations of zero stars for the zones — 2^ to —23° 10' are in 

 progress at Leitlen, Strassbiirg and Karlsruhe. Two of these zones 

 Lave been undertaken in the United States— 9° 50' to— 14° 20' at 

 Cambridge and —13° 50' to —IS© 10' at Washington. 



Star-charts. — Sections in and iv of the Southern Durchmust^rung 

 charts (sheets 48, 53-G3) have been published, bringing to a close that 

 most valuable work. Professor Schoufeld has issued with these last 

 numbers a short list of errata detected, which is reprinted in No. 2834 

 of the Nachrichten. 



A series of charts embracing all the stars visible to the naked eye — 

 that is, down to about the sixth and one-half magnitude — has been pub- 

 lished by Mr. Cottam, and has been very highly complimented. There 

 are in all thirty-six sheets, the scale being one-third of an inch to one 

 degree of a great circle. Another useful book of the same kind is 

 Klein's New Star-Atlas, which has appeared in both English and Ger- 

 man editions. There are eighteen maps, containing about the same 

 number of stars as Mr. Oottam's, and giving also alt the nebulae and 

 clusters visible in telescopes of moderate power — a great help to comet 

 hunters. 



STELLAR PARALLAX. 



Parallax of a Tauri. — Prof. Asaph Hall has published in No. 156 of 

 the Astronomical Journal, a determination of the parallax of a Tauri 

 from a series of observations with the 26-inch Washington equatorial, 

 extending from October 2, 1886, to March 15, 1887. The comparison- 

 star was an eleventh magnitude companion distant about 116", in posi- 

 tion angle 34o.5. The resulting values of the relative parallax are: 

 From measures of position angle, 7r=-f 0".163±0".0409; and from 

 measures of distance, 7r= + 0".035±0".0431. The mean value of the 

 l)arallax of a Tauri from these observations is, therefore, ;r=0".102± 

 0".0290. 



Prof. O. Struve, using the same comparison-star, recently obtained a 

 value nearly five times as great, namely, 7r=0".516±0".057. 



Parallax of 2 1510.— Dr. L. de Ball, of the observatory of the Univer- 

 sity of Liege, has determined in a similar manner the parallax of the 



