APEIL 10, 1903. J 



SCIENCE. 



587 



ress of the Zone Observations of the Astro- 

 nomisehe Gesellschaft.' 



All determinations of the positions of the 

 fixed stars through the time of Hevelins 

 (1650) were made without the use of the 

 telescope. The time of Flamsteed (1725) 

 marks the first use of the telescope for this 

 purpose. Bradley's star-place determinations 

 (1750) are considered to be the beginning of 

 the astronomy of precision. Among the 

 astronomers who led in the determination 

 of star places were: Lalande at Paris, 50,000 

 star places (1800) ; Piazzo at Palermo, 6,700 

 star places (1800) ; Eiimker at Hamburg, 70,- 

 000 star places (1835) ; Lament at Munich, 

 33,000 star places (1845). 



At the suggestion of Bessel the Berlin 

 Academy of Sciences (1825) undertook the 

 publication of star charts to contain all stars 

 visible with a 3-inch telescope to be executed 

 by different observers and to cover the belt 

 — 15° to -|-15° of declination. To furnish 

 a groundwork for these charts Bessel swept 

 over this area — 15° to -[-15° decl. in zones 

 with a meridian instrument, and determined 

 the places of a large number of stars fox 1825. 

 Later he extended his zones from -[-15° to 

 + 45° decl., embracing a total of 70,000 star 

 places between ■ — 15° and -f- 45° decl. Arge- 

 lander, a pupil of Bessel, extended Bessel's 

 zone determinations from -|- 45° to -|- 80° 

 decl. at Bonn (1842) with 22,000 star places, 

 and southward from — 15° to — 31° deck, 

 also at Bonn (1850), with 17,000 star places. 



Bessel expected that only a few years' time 

 would be required to complete the Berlin 

 Academy charts, but their execution dragged 

 along until 1860, when at last they were 

 finished. 



Because the Berlin Academy charts, then in- 

 complete, proved inadequate to satisfy the in- 

 creasing needs of astronomy, Argelander, with 

 his assistants at Bonn, in 1852 conunenced the 

 ' Great Bonner Sternverzeichniss ' to give the 

 approximate places of all stars visible with a 

 3-inch telescope from — 2° to -|- 90° declina- 

 tion, accompanied by an atlas of all the stars. 

 This great work, comprising 324,198 stars in 

 three quarto volumes with the atlas, was 

 finished in 1860. In 1886 Argelander's suc- 



cessor at Bonn, Schonfeld, extended this great 

 catalogue from — 2° to ■ — 23° declination in 

 a quarto volume containing 133,659 stars. 



The Astronomische Gesellschaft, founded in 

 1865, planned the first division of their great 

 zone catalogue to comprise accurate deter- 

 minations of the places of all the stars to the 

 9.0 magnitude, inclusive, contained in the 

 'Bonner Sternverzeichniss' from — 2° to 

 + 80° declination, the work to be distributed 

 among different observatories in zones of 

 about five degrees broad. The following ob- 

 servatories participated in this work: Kasan, 

 Dorpat, Ghristiania, Helsingfors, Cambridge 

 (U. S.), Bonn, Lund, Leiden, Cambridge 

 (England), Berlin, Leipzig, Albany (IT. S.), 

 Nikolajew. This series of catalogues in 

 fibfteen volumes has been published except the 

 Dorpat zone. These fifteen catalogues will 

 contain about 137,000 star places for the 

 epoch 1875.0. 



Immediately on the appearance of the 

 southern extension of the Bonner Sternver- 

 zeichniss ' by Schonfeld in 1886, the Astro- 

 nomische Gesellschaft arranged for the deter- 

 mination of all the stars to the 9.0 magnitude, 

 inclusive, in Schonfeld from — 2° to — 23° 

 declination. The following observatories 

 agreed to participate in this work : Strassburg, 



— 2° to — 6° declination; Wein-Ottakring, 



— 6° to —10°; Cambridge (IJ. S.), —10° 

 to — 14° ; the Naval Observatory, Washing- 

 ton, D. C, —14° to —18°; Algiers, —18° 

 to —23°. 



Wein-Ottakring has published the journal 

 of its zone observations — 6° to — • 10°; the 

 Naval Observatory has published the journal 

 for the zone — 14° to — 18° as Volume II. 

 of its publications, second series, 525 pages 

 quarto. The discussion of the results and 

 the preparation of the catalogue from the 

 Washington observations are in progress. 



Mr. E. A. Harris then pointed out ' The 

 Uses of a Drawing Board and Scales in 

 Trigonometry and Navigation.' The object 

 is to solve graphically spherical triangles. 

 The apparatus consists of a board about 

 40 X 20 inches, with angular graduations on 

 three sides radiating from the center of one 

 long side, and of edge scales graduated to give 



