24 ANNUAL REPORT SMITHSONIAN INSTITUTION, 192 8 



urgently needed structures which would cost in the neighborhood of 

 $1,000,000, namely: 1. Exhibition house for reptiles, amphibians, 

 and invertebrates. 2. Ape, lemur, and small mammal house, 3. 

 Pachyderm house. 4. Kemodeling of the carnivore house. 5. An- 

 telope, buffalo, and wild cattle house. 6. A wing to be added to the 

 bird house, with open air aviaries. 7. A proper fence around the 

 entire park. 



ASTROPHYSICAL OBSERVATORY 



The three field stations of the observatory, located at Table Moun- 

 tain, Calif.; Montezuma, Chile; and Mount Brukkaros, South West 

 Africa, have continued sending to the Smithsonian results of daily 

 observation of the intensity of solar radiation, and the United States 

 Weather Bureau published the daily values from Montezuma on the 

 Washington weather maps. 



A statistical study of the data accumulated at the Table Mountain 

 station led Mr. Fowle to discover a hitherto unsuspected influence of 

 variability in the ozone content of the atmosphere. Regular obser- 

 vations of ozone are now made at Table Mountain in cooperation with 

 Doctor Dobson, of Oxford, England. 



A new research undertaken by Mr. Aldrich under a grant from the 

 New York Commission on Ventilation was on the proi^ortion of loss 

 of heat of the normally clothed human body wliich should be ascribed 

 to radiation rather than to convection by the air. Long series of 

 novel and valuable experiments were made, using the melikeron, or 

 honeycomb pyranometer, for observing radiation of bodies at low 

 temperature, and a special thermoelectric temperature tester con- 

 structed for the research. The interesting results obtained, which 

 are summed up in the director's report appended hereto, will shortly 

 be published. 



The director undertook at Mount Wilson in the fall of 1927 and 

 again in the summer of 1928 to continue radiometer measurements of 

 the distribution of energy in the spectra of the stars. In the 1927 

 experiments the radiometer vanes, made of bits of house-flies' wings, 

 were sealed into a glass case in hydrogen, but after many trials the 

 apparatus proved useless because the mechanism required to rotate 

 the sj'stem so stirred up the gas that wholly unexpected motions re- 

 sulted. In 1928 an optically figured, fuzed quartz cylindrical vessel 

 was used, which was mounted on a brass support rotatable in a 

 ground joint. With this apparatus a high degree of success was 

 achieved, but as the results were obtained after the close of the year 

 under consideration, they will be described in next year's report. 



