22 AN^s'lAL EEPOKT .SM1THS0:N^IAX INSTITUTION, 1922. 



during the year. This work makes available for the exhibition of 

 hoofed animals a large area of comparatively level ground. Also it 

 will be possible to greatly improve the main automobile road through 

 the park. Extensive repairs were completed on the antelope house 

 and the older bear dens. Three large outdoor cages were Ijuilt for 

 certain birds, and mam^ minor repairs were completed during the 

 year. The most urgent need of the park is now a suitable restaurant 

 building to accommodate the greatly increased crowds of visitors. 

 The present small building is in bad condition and is entirely in- 

 adequate to meet the needs of the public. A suitable building could 

 be erected, using lumber in the possession of the park and employing 

 the regular park force, for about $20,000. Another urgent need is 

 for a new bird house, the old building, erected many years ago as a 

 temporary relief, being in a very bad state of repair. Moreover, there 

 is not sufficient space for the ver}'^ valuable and interesting collection 

 of birds and there is far too little room for visitors in the public 

 aisles. 



ASTROPHYSICAL OBSERVATORY. 



The outstanding feature of the year's work was the publication 

 of Volume IV of the Annals of the Astrophysical Observatory, a 

 quarto volume of 390 pages, which covers in detail the work of the 

 years 1912 to 1920. New instruments and methods of observing are 

 described and a mass of solar observations is presented and dis- 

 cussed. Many kinds of evidence are given to show the solar vari- 

 ability, and reference is made to applications of the results which 

 have been made by several meteorologists. 



The observing station erected on Mount Harqua Hala, Ariz., 

 through the generosity of Mr. John A. Roebling, has been much 

 improved, owing to the zeal of Mr. A. F. Moore, in charge of the 

 station. Solar constant observations were made on upward of 70 per 

 cent of the days of the yesLV. Comparisons made during and after 

 a visit b}'^ the director show no change in the scale of pyrheliometry, 

 so that the results from this station are comparable with those at 

 Montezuma, Chile. Earlier in the year the director visited the 

 station at Montezuma, where he revised all the adjustments of appa- 

 ratus and some of the methods employed there. 



In June the director and Mr. L. B. Aldrich proceeded to the 

 Smithsonian station on Mount Wilson, Calif., Avhere a beginning 

 was made toward installing new " solar constant " apparatus to re- 

 place that removed to the new Arizona station in 1920. By antici- 

 pation it may be said that later results were secured on the dis- 

 tribution of energy in the spectra of 11 of the brighter stars by 

 bolometric work in connection with the hundred-inch telescope, and 



