694 PROGRESS OF ASTRONOMY FOR 1891 AND 1892. 



C Ursa' M((jori,s. — TLe duplicity of C Ursue Majoris is not so vSatisfac- 

 torily confiruied. Tlie niaxinmm relative velocity of its two coui- 

 poiieiits seems to amount to about 100 miles per secoud. 



a Booth. — Mr. Keeler's recent measures upon the D line of tlie spec- 

 trum of Arctnrns show that the velocity in the line of sight is not 80 

 kilometers per second, the value hitherto accepted, but 6.4 kilometers, 

 which accords with the result obtained by l)r. Vogel. The mean of the 

 measures at Potsdam from October 5, 1888, to May 23, 1890, is —7.1 

 rt 0.3 kilometers. The Lick observations from April 20, 1890, to August, 

 15, 1890, give — C.9 kilometers. 



ASTRONOMICAL PIIOTOORAPHY, 



The photographic chart of the sl'y. — The third* meeting of the perma- 

 nent committee, appointed by the Astrophotographic Congress at Paris 

 in 1887, was held at the Paris observatory from March 31 to April 4, 

 1892. Admiral Mouchez presided, the menibers of the committee i)res, 

 ent being Baillaud, Bakhuyzen, Beuf, Christie, Denza, Donner, Gill- 

 Henry (Paul), Henry (Prosper), Janssen, Kapteyn, Loewy, Mouchez, 

 Pujazon, Eayet, Eicco, Tacchiui and Trepied. The following astrono- 

 mers were also present by invitation, Messrs, Abney, Audoyer, Belo- 

 polsky, Bouquet de la Grye, Cornu, Knobel, Gautier, Maturana, Plum- 

 mer, Scheiner, Tisserand, and Wolf (C). 



Drs. Bakhuyzen and Gill were elected vice-i)residents and Prof. 

 Kapteyn and Trepied secretaries. 



From reports of progress made at different observatories the follow- 

 ing notes indicate the advancement of the work: 



Some delay had been experienced in securing the plates containing 

 the referen<!e lines or "■ reseaux,^^ but provision was finally made to 

 furnish them at an early day, as well as the photographic plates which 

 it was necessary should be of a specially good quality of plate glass. 



Algiers. — Instruments ready and only awaiting the plates and '* reseait." 



Bordeaux. — PLotogra|ihic installation has been ready for about a year; a number 

 of experimental photographs liave been taken and the work can commeiioe as soon 

 as a supply of plates is secured with the necessary "re'seaii." 



Cape of Good Hope. — Instrument practically ready. 



Catania. — The instrument has been completed. 



HeJsinf/fors. — The instrument lias been ready for several months and a consideral>le 

 number of photogra})hs have been taken. 



La Plata. — Instrument ready. 



Melbourne. — Instrument ready and a number of experimental ])lates have bei'n 

 secured. 



Oxford. — Instrument ready and a number of plates submitted to the committee. 



* The first meeting df the committee, for organization, etc., was held at the time of 

 the Congress in April 1887, the second meeting or the first regular meeting for dis- 

 cussions, in September, 1889 (not 1890, as stated by a misprint in the review of As- 

 tronomy for 1889-'90). 



