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GOULD REDUCTION OF D AGELET S OBSERVATIONS 



for the determination of At and n, but on which several stars of Argelander's catalogue 

 occur. The clock-error and quadrant-deviation being calculated independently bj T means of 

 Argelander's stars, and by means of positions derived from stars observed by d'Agelet on 

 other dates, the two determinations agreed so closely that it was entirely insignificant which 

 should be used, the differences being only in the second decimal. For the sake of consistency 

 the results from our catalogue have been emploj'ed. 



In concluding these introductory remarks, I will place together the positions of those stars 

 which have defied attempts at identification, or whose discordances are too great to be lightly 

 disposed of by a conjecture. Among them are, not improbably, places of planets and of variable 

 stars, but the greater part of them must, I am inclined to believe, owe their place in the 

 catalogue to some error in the original record. 



In addition to the motives already mentioned as having prompted me to undertake this 

 reduction and catalogue, an especial incentive was found in the experience which it would afford 

 and make available for a much more extended work which has long been a cherished project, 

 the recomputation of Piazzi's observations, and the formation from them of a new catalogue. 

 This is an enterprise far too extensive for the powers of a private individual, but I look forward 

 with much hopefulness to the possibility of obtaining the requisite means at some future time. 

 The elaborate publication of the originals by Prof. Littrow, in the annals of the Vienna 

 Observatory, will much facilitate this undertaking, and I have already completed the prelim- 

 inary tables to a considerable extent. It is upon the observations of Piazzi that the reduction 

 of Lalande's zones is based, and to them the astronomer of to-day is continually compelled to 

 resort for his knowledge of a large proportion of the "landmarks of the heavens." No astro- 

 nomical labor promises richer usefulness than this ; and if the great work of reducing anew the 

 observations of Bradley be carried out by a combination of the astronomers of Europe, as is 

 now proposed, nothing seems more appropriate for the astronomers of the New World than to 

 render a similar service by a new reduction of the Storia Celeste. 



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