THE FUTURE OF ASTRONOMY m 



A third, and perhaps the best, method of making a real advance in 

 astronomy is by securing the united work of the leading astronomers of 

 the world. The best example of this is the work undertaken in 1870 

 by the Astronomische Gesellschaft, the great astronomical society of 

 the world. The sky was divided into zones, and astronomers were in- 

 vited to measure the positions of all the stars in these zones. The 

 observation of two of the northern and two of the southern zones were 

 undertaken by American observatories. The zone from +1° to +5° 

 was undertaken by the Chicago Observatory, but was abandoned owing 

 to the great fire of 1871, and the work was assumed and carried to com- 

 pletion by the Dudley Observatory at Albany. The zone from +50° 

 to +55° was undertaken by Harvard. An observer and corps of 

 assistants worked on this problem for a quarter of a century. The 

 completed results now fill seven quarto volumes of our annals. Of the 

 southern zones, that from — 14° to — 18° was undertaken bv the 

 Naval Observatory at Washington, and is now finished. The zone from 

 — 10° to — 14° was undertaken at Harvard, and a second observer 

 and corps of assistants have been working on it for twenty years. It is 

 now nearly completed, and we hope to begin its publication this year. 

 The other zones were taken by European astronomers. As a result of 

 the whole, we have the precise positions of nearly a hundred and fifty 

 thousand stars, which serve as a basis for the places of all the objects 

 in the sky. 



Another example of cooperative work is a plan proposed by the 

 writer in 1906, at the celebration of the two-hundredth anniversary of 

 the birth of Franklin. It was proposed, first to find the best place 

 in the world for an astronomical observatory, which would probably be 

 in South Africa, to erect there a telescope of the largest size, a reflector 

 of seven feet aperture. This instrument should be kept at work through- 

 out every clear night, taking photographs according to a plan recom- 

 mended by an international committee of astronomers. The resulting 

 plates should not be regarded as belonging to a single institution, but 

 should be at the service of whoever could make the best use of them. 

 Copies of any, or all, would be furnished at cost to any one who wished 

 for them. As an example of their use, suppose that an astronomer at 

 a little German University should discover a law regulating the stars 

 in clusters. Perhaps he has only a small telescope, near the smoke 

 and haze of a large city, and has no means of securing the photographs 

 he needs. He would apply to the committee, and they would vote that 

 ten photographs of twenty clusters, each with an exposure of an hour, 

 should be taken with the large telescope. This would occupy about a 

 tenth part of the time of the telescope for a year. After making copies, 

 the photographs would be sent to the astronomer who would perhaps 

 spend ten years in studying and measuring them. The committee 



