XXII 



more than fourteen years : volume after volume has been issued with 

 a regularity hitherto unsurpassed ; while the high character for accu- 

 racy of the star-places in each annual catalogue has been fixed by the 

 unanimous approval of the most eminent European authorities. To 

 render this great work complete, however, required the reduction of 

 every individual observation to a fixed epoch, and the incorporation of 

 the whole into one general catalogue. Much yet remained to be done, 

 though the work was fast progressing ; and had its lamented author 

 been spared another year or two, he would have presented to astro- 

 nomers a monument of industry and devotion to duty unsurpassed 

 in the annals of British science. The point now most to be desired, 

 previous to the publication of the final catalogue, is, a rigorous 

 investigation of the errors of division of the Meridian Circle, which 

 has not yet been attempted, owing to the too numerous and pressing 

 pursuits of the unwearied and enterprising Director. 



In 1854 a new project was commenced, 'A Catalogue of Remark- 

 able Objects,' comprising all stars of suspected large proper motion, 

 the binary systems, variable and coloured stars, all bright stars down 

 to the third magnitude, and indeed whatever of interest was obser- 

 vable with a four-inch object-glass. In the discussion of proper 

 motion Mr. Johnson's plan of procedure was that adopted by 

 Madler, viz., instead of deducing the change of place from two most 

 widely distant authorities alone, to employ all published positions, 

 and thus to deduce the best possible final value ; leaving no broken 

 link, no contradictory observation uncorrected, or at least unnoticed, 

 to raise future discussion as to the value derived. Such a method 

 is of course the most laborious, but nothing less can be regarded as 

 definitive, and, to secure the best results, neither time nor trouble was 

 spared. 



The most eventful epoch in the history of the Radcliffe Obser- 

 vatory and of its late Director remains to be noticed, viz. the establish- 

 ment of the fine heliometer a treasure unique in its improvements, 

 unrivalled in its marvellous powers, but almost the labour of a life 

 to develope and turn to the best account. It was erected by its 

 makers, Messrs. Repsold of Hamburg, in October 1849, and was 

 forthwith employed in incessant and toilsome research by its skilful 

 manipulator. The Radcliffe Trustees, with their usual liberality, not 

 only provided and equipped this very costly instrument, but, in order 



