282 



THE SAYRE OBSERVATORY. 



however, such corrections have been applied in all cases where they were; available, 

 although it would seem that any one who has had occasion to examine somewhat closely 

 into this subject, must agree with Newcomb's conclusion that the correction for system- 

 atic errors has in recent limes been carried too Gar. 



As the Declinations were reduced in advance of the Right Ascensions, a number of 

 catalogues became available for the latter which were not employed for the former. It is 

 also to be observed that the list embraces several catalogues which give one coordinate 

 only. Where the name is followed by the symbol a, the catalogue has been employed 

 only for the Right Ascensions; when Col lowed by the symbol 8, only for the 

 Declinations. 



In the explanatory notes s designates the systematic correction in Right Ascension ; 

 .s'' designates the systematic correction in Declination ; ]> designates the weight of the 

 Right Ascension ; p' designates the weight of the Declination ; t the mean date of obser- 

 vation. The system of weights employed will be spoken of in connection with the 

 method of reduction. 



List of Catalogues. 



1, Bradley. 1755. None Reduction der Bradley'schen Beobachtungen aus don Jahren 1750 bis 1702. Von 



Arthur Auwers. St. Petersburg, 1888. 



2, Mayicu. 1755. Tobias Mayer's Sternverzeichniss nach don Beobachtungen auf der Gottinger Sternwarte in 



don Jahren 1756 bis 1700. Neu bearbeltet von Arthur Auwers. Leipzig, 1894. 

 Si. Fedobenko's Lalande, 1700. Positions Moyenne pour l'Epoque do 1790,0 des Etoiles Cireumpolaire, dont 

 les observations ont eto publices par Jerome do Lalande dans les Mlmoires do I'Academle do Paris do 1789 el, 



o 



1790. Par Ivan Pedorenko. St. Pelersbourg, 1854. s = J (Abo [ Bessel's Bradley); p same as 2 ; t from 

 Histoire Celeste. 



4. Lalande. 1800. A Catalogue of those Stars in the Histoire Cfilcste Franchise of Jerome do Lalande for 



which tables of reduction to the epoch 1800 have been published by Prof. Schumacher. Francis Baily, Esq, 

 This catalogue was used for a low stars where other early authorities wore wanting or doubtful. For decli- 

 nations the places were taken directly from Baily's Catalogue, p 1 0.1. For right ascensions Von Asten's 

 tnldes were used, p same as 2; t from Histoire Celeste. 



5. ISossurt (a). 1800. Supplement a l'Histoire C6lestc do Lalande. Catalogue do o950 etoiles ramenees a 



1'equinoxe do 1800. Far M, .1. Bossert. Paris, 1892. p same as 2. 

 0. d'Abelet. 1800. Reduction of the Observations of Fixed Stars made by Joseph Lepaute d'Agelet at Paris in 

 1783-1785, with a, catalogue of the Corresponding Moan Flaoos referred to the equinox of 1800,0. By P.. A. 

 Gould. Washington, 1800. 



s = 0M3. 



s> = Piazzi — 1''.42 0" to XIP. 



»' — Piazzi + 1».22 XIP to XXrV". 



p same as 2. 



7. Piazzi. 1800. Prascipuarum stellarum inerrantium Positiones Mediro Incunto Seeculo xix ox observa 



tionibus habitas in Specula Panormitana ab anno 1792 ad annum 1818. Panormi, 1814. t from original 

 observations. Right ascensions of stars north of 65° declination not used. 



8. Groombridse. 1810. A Catalogue of Circumpolar Stars deduced from the observations of Stephen Groom- 



bridge at Blackheath Observatory. Edited by George Biddell Airy, Esq. London, 18118. 



