NOTES UPON THE EUNDAMENTAE SYSTEM 



OF STARS. 



Bv F. A. BELLAMY. Hox. M.A.. F.K.A.S. 



Of all the branches into which astronomical work 

 may be divided there is none of greater importance, 

 none to which more time has been devoted at the 

 observatories during the past two hundred and fift\' 

 \ears, and none that has proved so useful in our 

 dailv life, as meridional or star-catalogue work. 

 Some hundreds of star-catalogues e.xist, small or 

 great, and the aim of all has been to re-obser\'e the 

 brighter stars and obtain improved positions, and to 

 observe and determine the positions of other and 

 fainter stars ; the object being to fix or ascertain a 

 large number of points of reference in the skw much 

 as geographers do uiion the earth. 



The object of these notes is to draw attention to 

 perhaps the most important piece of work ever 

 undertaken in this branch, and to place before our 

 readers a general summar\- of the proceedings which 

 led to its being started, and of the present condition 

 or progress already made. 



Some remarks will be made upon the scheme 

 [jroposed, the pecuniar)' and other help received b}' 

 the Dudley Observatory, the erection of a southern 

 obser\'ator\-, the inauguration of the work there, 

 also attention will be called to future proposals and 

 ultimate aims; and, finalh'. a translation from the 

 Spanish of an important paper b\" Professor R. H. 

 Tucker, dealing with the actual details of the work 

 and its progress at San Liii/, in Argentina, up to last 

 Julv, will be appended. 



The success of the great scheme depends upon 

 three sources: Professor Boss, who has initiated, 

 planned, and is natural!}' at the head of the work; 

 Professor R. H. Tucker, the most eminent meridian 

 worker, who has charge of the observational part : 

 and the Trustees of the Carnegie Institution of 

 Washington, who have provided the mone\'. 



The headquarters of the work will be at the 

 Dudle\' Observator\', whose director is Professor 

 Boss ; the thousands of stars selected for observation 

 were first observed there, then the same meridian 

 instrument was taken to the southern obser\'ator\- 

 at San Luiz, and when the instrument has been 

 returned to Albany, the stars at first observed there 

 will be re-observed. There are various excellent 

 reasons why this should be done. 



The Dudley Observator\-, near Albany, U.S.A., 

 %\as founded in 1S51, by subscription, principally 

 aided by the generous donation of Mrs. B. Dudley — 

 hence its name. It was organised in 1856, and placed 

 under the direction of Dr. B. A. Gould. Until 

 1877 it was chiefly a nieteorological observator\', 

 but in 1878 a section of the Astronomische Gesell- 

 schaft scheme for the re-observation of all the 

 Bonn Durchmusterung stars as bright as the ninth 



magnitude, and a considerable selection of others 

 a few tenths of a magnitude fainter, was under- 

 taken at the Observatorv ; the work of re-observing 

 8,241 stars between +5" 10' was commenced on 

 .\ugust 19th, 1878, and completed on August 5th, 

 188.Z; each star was observed twice or more times. 

 Professor Boss was engaged on the Zone observa- 

 tions and reductions throughout ; the assistants. 

 O. H. Landreth, T. I). Palmer, and R. H. Tucker 

 were helping for one, three and four years 

 respectively. Of Mr. Tucker, who was in charge of 

 the whole work during Professor Boss's absence in 

 Chili to observe the Transit of \'enus. in December, 

 1882, the Director has acknowledged that " the 

 recortl of observation and cominitation bears, 

 throughout, high testimony to the character of 

 his efficienc\' and zeal." This catalogue of 8,241 

 stars was published in 1890 and was one of the 

 first two published in connection with that great 

 and important scheme. It was accomplished by 

 means of the Olcott Meridian Circle — so named 

 from a generous donor of funds — constructed by 

 Pistor & Martins of Berlin, in 1856, and is of 

 eight inches aperture and ten feet focal length. 



The position of the Observator\' there was 

 4'' 54'" 59^-2 W. of Greenwich and 42" 39' 49"- 5 

 north latitude; it was one hundred and se\'ent}' feet 

 abo\e the sea and situated on the northern side of 

 the city of Alban_\' in the valley of the Hudson river. 

 Ow ing to the smoke and disturbance from engines 

 and trains from the railway and from the frequence 

 of local mist and fog, good work was interfered with, 

 so much so that it seemed advisable, if not imperative, 

 that the observatory be refounded on a new site; 

 the mone\' was forthcoming — as is usual for 

 astronomy in the U.S.A. — and about 1893 the 

 observatory was rebuilt on its present site, not 

 very far from its original locality. Besides the 

 Olcott Circle its other chief instrunient is an 

 equatorial telescope of twelve-and-a-quarter inches 

 aperture by Brashear, \\'arner & Swassey. The 

 exigencies of the meridian work have prevented the 

 equatorial being much used. It is this Olcott Circle 

 that has been temporarily moved to San Luiz. 



Since the Observatory has been under the direction 

 of Professor Lewis Boss, the chief work has been 

 meridian observations, researches ujion proper 

 motions, and motion of the solar s\'stem. The most 

 recent work has been the observation and preparation 

 of a catalogue of positions and proper motions of all 

 stars to the seventh magnitude, in connection with 

 the department of Meridian Astrometry of the 

 Carnegie Institution of \\'ashington, which Institu- 

 tion has ajiproprialed to the Dudley Observatory, 



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