SECRETARY'S REPORT 69 



accurate computing system, should make possible the calculation of 

 the position of the satellite at any moment and the relative position 

 of the stations in respect to each other and to the center of the earth 

 with a precision of some 30 feet. Not only is such precision tracking 

 essential to the general scientific value of the Artificial Satellite Pro- 

 gram, but it will lead specifically to precise determination of the 

 atmospheric density and pressure as a function of height to an altitude 

 of some 300 to 500 miles above the earth's surface. It will provide 

 a precise interconnection among the geodetic networks of the conti- 

 nents and islands, the inclination of these networks with respect to 

 the true geoid, the shape of the earth, certain gravimetric data con- 

 cerning the distribution of mass in the earth, and other geophysical 

 information of great significance. 



The visual tracking program will have two aspects : (1) Acquisition 

 of a satellite in case the electronic tracking equipment contained in 

 the satellite should fail, as well as possible tracking near the end of 

 a satellite's lifetime as it plummets through the lower atmosphere ; and 

 (2) a broad contribution to general interest in scientific research by 

 young potential scientists as well as the general public. The visual 

 observations will be carried out by a large number of nonprofessional 

 observers under the general direction of Dr. Armand N. Spitz. It is 

 expected that between one and two thousand observers, usually amateur 

 astronomers, will be activated in this program, but many times that 

 number will follow the program in considerable detail and gain scien- 

 tific understanding and interest because of it. 



The organization of the visual observation part of the program 

 is well under way, and the first of a series of bulletins has been pre- 

 pared and issued to more than 20,000 potential observers. 



The participation of the Smithsonian Astrophysical Observatory 

 in the Artificial Satellite Program follows two traditions that we 

 cherish in the Smithsonian Institution. We are participating as 

 pioneers in the progress of science, comparable to Dr. Langley's origi- 

 nal research in the flight of heavier-than-air craft. We are also 

 promoting international interest in the Satellite Tracking Program 

 which is in keeping with the worldwide pattern of contributions to 

 knowledge by the Smithsonian Institution. 



DIVISION OF RADIATION AND ORGANISMS 

 (Prepared by R. B. Withrow, Chief of the Division) 



The major activities of this division have been concerned with 

 fundamental physiological and biochemical research on the role of 

 light in regulating growth in higher plants. Seed germination, seed- 

 ling growth, flowering, and the development of what is commonly 

 referred to as a "normal plant" are controlled by light. Pigments 



