10 



SCIENCE. 



[N. S. Vol. XIV. No. 340. 



ine pictures of the solar appendage. The 

 results were regarded by many as genuine, 

 while others doubted. Much discussion 

 followed, some of it slightly fervid in tem- 

 perature. 



However, the test was simple as soon as 

 an opportunity could be had for applying 

 it. The eclipse of 1886 gave the wished-for 

 opportunity. Photographs taken during 

 totality were compared with those taken by 

 Huggins's process, but alas ! the results were 

 far from identical. The supposed coronal 

 forms were therefore fictitious. 



Though much in the way of detail has 

 been learned of the corona in connection 

 with recent eclipses, it still remains very 

 much of an enigma. Unless some new 

 method may be found for attacking the 

 problems which it presents, apparently 

 their complete solution will be long de- 

 layed. Here too, as in other cases, the solu- 

 tion of one problem is likely to suggest a 

 score of new ones, so that eclipse expedi- 

 tions seem unlikely soon to be exclusively 

 things of the past. 



At the opening of the century, it can 

 hardly be said that astronomers were in 

 possession of more than two or three cata- 

 logues of stars which would be of any use 

 whatever for the exact astronomy of to- 

 day. Even these were of quite limited ex- 

 tent as regards the number of stars con- 

 tained. There were, it is true, a number of 

 such catalogues based upon the imperfect 

 methods of the previous century, and a 

 considerable amount of valuable material 

 in the form of unreduced observations ex- 

 isted, but the latter was of little practical 

 service so long as it remained in this form. 

 Even if accessible, which was not always the 

 case, very few could undertake the drudgery 

 of searching through the records for the 

 wished-for material, and when found, if 

 found at all, to apply the reductions neces- 

 sary to prepare it for practical use. It is 

 to George Biddel Airy, who became Astron- 



omer Eoyal in 1835, that astronomers owe 

 the introduction of the present practice 

 of reducing and publishing observations 

 promptly, thus making them accessible to 

 all. 



The most valuable series thus buried out 

 of sight at the beginning of the century 

 was that of Bradley. The observations 

 were made at G-reenwich between the years 

 1750 and 1762. These were first rendered 

 accessible by Bessel, who in 1818 published 

 under the title ' Fundamenta Astronomiae,' 

 a catalogue of 3112 stars constructed 

 from all Bradley's observations. More re- 

 cently a re-reduction has been published 

 by Auwers, in which every refinement 

 which the present state of science could 

 suggest has been employed, in, order to ob- 

 tain from them the best possible results. 

 This catalogue is of special value in such 

 investigations as involve the stellar mo- 

 tions, the remoteness of the time of obser- 

 vation — 140-150 years — being a great ad- 

 vantage in this respect. There was also a 

 great mass of observed star places, the re- 

 sult of the untiring industry of LaCaille, 

 D'Agelet and Lefrangais Lalande, nephew 

 of the more widely celebrated astronomer. 

 Most of this material was only placed in 

 an accessible form after the nineteenth cen- 

 tury was far advanced, the last contribution 

 being the publication by our own Dr. Gould, 

 in 1864, of the final reduction made under 

 his direction of the observations of D'Age- 

 let, all reduced to the epoch 1800. 



The beginning of the century found Piazzi 

 busily engaged at his observatory in Pal- 

 ermo accumulating material for his famous 

 catalogue of 7646 stars, which finally ap- 

 peared in 1814. As he possessed for this 

 purpose an instrument superior to anything 

 previously constructed, and was himself a 

 careful and most industrious observer, this 

 catalogue has been of very great value. A 

 re- reduction of the observations is now in 

 progress, based upon the more accurate 



