134 RECORD OF SCIENCE FOR 1887 AND 1888. 



Helsivgfors-Gotha, 650-55°.— Catalogue fiuisliod to tbo precessious; 0'' ready for 



press. 

 Cambridge (Harvard), 55°-60°. — Rednctious nearly coaipleted. 

 Bonn, 50°-40°. — Reductions -well advanced. 

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



Leiden, 35O-30°. — Zones printed, and precessions for catalogue partly finislied. 

 Cambridge (Englaud), 30O-25°. — Observations nearly complete; reductions proceeding 



rapidly. 

 Berlin, 250-30°. — Reductions nearly fiuisbed. 

 Berlin, 200-15°. — Reductions under way. 

 Leij)zig, 1.50-5°. — Observations practically finished. 

 Albany, 50-]o. — In press. 

 Nicolaief, -\-l° . . . — 2o. — Observations finished; reductions progressing. 



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

 progress at Leiden, Strassburg and Karlsruhe. Two of these zones 

 have been undertaken in tl^ United States— 9° 50' to— 14° 20' at 

 Cambridge and -13° 50' to -18° 10' at Washington. 



Star-charts. — Sections iii and iv of the Southern Durchmusterung 

 charts (sheets 48, 53-03) have been published, bringing to a close that 

 most valuable work. Professor Schonfel* 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. Cottam's, and giving also all the nebulse and 

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

 hunters. 



STELLAR PARALLAX. 



Parallax of a Tauri.—Vvof. 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 2G-inch Washington equatorial, 

 extending from October 2, 1880, to March 15, 1887. The comparison- 

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

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

 From measures of position angle, 7r=-f-0".lG3ztO".0409; and from 

 measures of distance, ;r=4-0".035±0".0431. The mean value of the 

 l)arallax of a Tauri from these observations is, therefore, 7r=0".102± 

 0".029G. 



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

 value nearly five times as great, namely, 7r=0".51GiO".057. 



Parallax of 2 1516.— Dr. L. de Ball, of the observatory of the Univer- 

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



