DEVELOPMENT OF THE PLANETARIUM — CHAMBERLAIN 273 



transition from fantasy to fact in the areas of rocketry and astro- 

 nautics. In many institutions, money for program expansion was 

 available, and in numerous cities, committees of interested citizens 

 sought new public service educational agencies. More widespread 

 travel and consequent exposure to existing planetariums whetted the 

 appetite. 



MORRISON PLANETARIUM 



In San Francisco, during the latter 1940's, the decision was made to 

 construct a planetarium. Funds were raised by the trustees of the 

 California Academy of Sciences for the purpose, beginning with a 

 gift of $200,000 from the estate of Alexander F. Morrison. No 

 planetarium instrument was available, however, so the Academy 

 undertook to construct one in the excellent shops that had been used 

 to repair optical and navigation instruments for the Navy during the 

 war. Certain basic features of the Zeiss instrument were incorporated 

 but many improvements were made. As Dr. Eobert C. Miller, di- 

 rector of the Academy, expressed it : 



This is the first planetarium that can be operated entirely automatically. 

 While it is the intention in general to have "live'' planetarium demonstrations, 

 if the lecturer is suddenly called away by some emergency, he can flick a 

 switch and a tape recording will take over, giving the lecture, dimming the 

 house lights, turning on the stars, putting the planets through their proper 

 motions in perfect synchronization with the lecture, finally bringing the 

 daybreak and sunrise, then turning on the house lights, thanking people 

 for listening, and inviting them to come again. Actually of course we will 

 never leave the planetarium unattended while a show is in progress; but if 

 a lecturer develops a bad throat the tape will come in handy. 



The automatic feature is provided by a telephone-type switchboard which 

 can be plugged in to accomplish, by a stepping relay, 250 operations in 

 succession on cue from the tape, the cue being provided by bits of foil on 

 the back of the tape which complete an electric circuit. 



The Academy of Sciences projector is quieter in operation than earlier 

 instruments. The hemispheres containing the star plates have been brought 

 closer to the center, giving a better distribution of weight and improving 

 the appearance. The planet projectors, which are light in construction, have 

 been put at the two ends of the instrument, instead of at the "waist" as in 

 the Zeiss design. The "eyelids" which cut off the light of the stars when 

 they reach the horizon are more positive in operation. The moon is not 

 just a round white disc but an actual photograph of the moon projected 

 on the dome. The stars themselves give a greater illusion of reality. (Miller, 

 1952, p. 17.) 



Since its opening in November 1952, the Morrison Planetarium 

 has taken its place among the institutions of the country seeking to 

 bring astronomical science to the general public. 



SPITZ PLANETARIUM PROJECTORS 



Another series of developments in the latter part of the 1940's 

 has considerably changed the planetarium picture in the United 



