PRESIDKNT S ADDRESS. 1 I 



universe which a few years ago seemed unattainable. The im- 

 mensity of the task when tackled by the old methods seemed so 

 great, and the consequent delay so inevitable, that Kapteyn pro- 

 posed that astronomers should concentrate their attention on 

 certain selected areas which might be taken as representative 

 samples of the whole sky. 



A rude analogy will perhaps help us. The old way was 

 something like studying the condition of England by means of a 

 " Burke's Peerage " or a " Who's Who." Kapteyn proposed as 

 better a limited number of selected areas, some urban, some 

 rural ; l)ut the blink method will easily cover the whole area and 

 permit an exact census to be taken. 



The present state of astronomical science is one of great 

 activity, but I have only time to make some brief references. The 

 activities of the Union Observatory, an institution which was 

 oriorinallv started bv our Association, call for some mention. 

 The late Mr. Franklin- Adams planned a photographic chart 

 of the whole sky, and more than half of the plates were 

 taken at the Union Observatory. These were forwarded 

 to the Astronomer Royal at Greenwich, and are undergoing ex- 

 amination. Some of the first results of this examination have 

 been published in the " Memoirs of the Royal Astronomical 

 Society." Counts of the stars on these plates have been made 

 by Messrs. Chapman and Melotte,* from whom the following 

 figures are taken : — 



Plates Plates 



Galactic taken in taken in 



Latitude. S. Africa. England. 



o° to 15° 988,000 515,000 



16 to 30 616,000 383,000 



31 to 50 406,000 230,000 



51 to 90 307.000 145,000 



This little table invites two comments — one is that the p-arity 

 of the atmosphere has resulted in many more stars (nearly twice 

 as many) being found on the plates taken at the Union Observa- 

 tory ; the other that the richness of the plates decreases more or 

 less uniformly as the (ialactic Plane — the Milky Way — is left. 

 Chapman and !\lelotte also give this table, showing the total 

 number of stars in the sky, arranged according to magnitudes : — 



Magnitude. Number. 



2.0 38 



3.0 III 



4.0 300 



5-0 • 950 



6.0 3,150 



7.0 9,810 



8.0 3-2,360 



9.0 97400 



lo.o 272,000 



II .0 698,000 



* Mem. R.A.S. 60 I4I. 



