08 



THE GREAT COMET OF 1858 



me that it has not been wasted ; the good effect is apparent, particularly in 

 the Liverpool and Gottingen observations. 



A catalogue of all the stars used for comparison having been formed, the 

 following authorities were consulted for material : 



Baily's Lalande, Piazzi, Bessel's Zones (Weisse's Reduction), Struve Catalogus 



- 



Generalis, Taylor, RUmker, Argelander's Southern Zones (Oeltzen), Robinson's 

 Armagh Catalogue, Johnson's Radcliffe Catalogue, Greenwich Twelve Year and 

 Six Year Catalogues, Madler, Greenwich Observations, 1854-60, Henderson Edin- 

 burg Observations, Challis Cambridge Observations, Leverrier Paris Observations, 

 1856-59. 



Leverrier commenced, in 1856, to reobserve the stars of Lalande; hence 

 quite a number of the stars the observers had taken from this source, were 

 found in the Paris Observations. The searching them out and reducing them 

 entailed considerable labor. In addition to the material before mentioned, that 

 furnished by the observatories at which the comparison stars were reobserved, 

 was, of course, not omitted. 



All this material was reduced to 1858.0, and to the standard of Wolfer's 

 Tabulae Reductionum, by applying the systematic corrections given by Auwers 

 in Astr. Nachr., No. 1300, with the modifications suggested by Mr. Safford, in 

 No. 1368. The systematic corrections for Robinson are found in Astr. Nachr, 

 No. 1408. Also, the following, kindly furnished by Mr. Safford, were employed: 



1 







Greenwich Six Year Catalogue, . . . -f-0 8 .017 



E. A. »EC 



Paris 



1854-60, . . . +0 .027 -f0"70 



-59, . . . -f 0.056 4-0.19 



In a few cases, mostly Piazzi stars, where the observations indicated proper 



motion 



was taken into account. With regard to the stars used in 



the 



southern observations, those common to the northern being excepted, they were 

 retained without change, or when the same star had been used at both observer 



ones, the observations were combined, allowing a weight of 3 to the Cape and 

 No J° ^ Santiag ° observation - However, the place of the Santiago star 

 henc! V q T l6nt t0 ° ape Na 95 ' is ™»& se <™^y ^ error of reduction; 



ence the Cape place has been adopted. And Santiago, No. 49, differing f A 

 m decimation, from 



the W 7 T e< * mvalent > Cape No. 87, the Cape declination appearing 



tne better, has been retail F 



