44 KEPORT OF THE SECRETARY. 



With regard to the birds, more is being done for the better 

 care of the larger ones. There has been designed and partly 

 constructed a large "flying cage," capable of including tall 

 trees within it, which is to be built near the present bird 

 house. The cage will be supplied with running water, and it 

 is hoped that some of the aquatic species may live within its 

 limits. 



THE ASTROPHYSICAL OBSERVATORY. 



The most prominent feature of the year's work has been 

 the distribution of the first volume of Annals of the Astro- 

 physical Observatory, to which attention was directed in 

 my report of last year. This special volume has been sent 

 to 1,500 Government depositories, observatories, learned 

 societies, and to eminent astronomers and physicists through- 

 out the world. The work will, it is believed, establish an 

 enduring reputation for the observatory from which it pro- 

 ceeded. 



The eclipse expedition to Sumatra is spoken of more at 

 length in the detailed report of the Aid Acting in Charge, 

 which will be found in the Appendix. The special occasion 

 for this expedition arose with reference to the observations 

 made under the Government appropriation by the Institution 

 in the solar eclipse of May 28, 1900, at Wadesboro, N. C. 

 These, though valuable, were not in themselves complete, and 

 pointed to conclusions of particular interest which demanded 

 the opportunity of another eclipse to definitely perfect them. 



Perhaps the most interesting of these was the incomplete 

 evidence secured on a single photograph of the existence of 

 several small planets within the orbit of Mercury, as indicated 

 in Plate XVIII of the last year's report. Prof. E. C. Pick- 

 ering, to whom this photograph was referred for his expert 

 judgment, saw nothing in the appearance of the photographic 

 impressions of the supposed planets which would lead him to 

 pronounce them spurious. To make certain of their genuine- 

 ness would, however, required the evidence of another photo- 

 graph, and new photographs were only to he supplied by 

 another eclipse. 



A second, not absolutely conclusive, observation of great 

 interest was that made by the bolometer on the heat of the 

 inner corona, from which, as stated on page 154 of the Smith- 



