ADVANCE OF ASTRONOMY. 201 



intertwined spirals of fainter stars, which become 

 richer and more intricate in the irregularly rifted 

 zone of the Milky Way. 



" We, who form part of the emblazonry, can only 

 see the design distorted and confused ; here crowded, 

 there scattered, at another place superposed. The 

 groupings due to our position are mixed up with those 

 which are real. 



" Can we suppose that each luminous point has no 

 other relation to those near it than the accidental 

 neighbourship of grains of sand upon the shore, or 

 of particles of wind-blown dust of the desert ? Surely 

 every star from Sirius and Vega down to each grain 

 of the light-dust of the Milky Way has its present 

 place in the heavenly pattern from the slow evolving 

 of its past. We see a system of systems, for the broad 

 features of clusters and streams and spiral windings 

 which mark the general design are reproduced in 

 every part. The whole is in motion, each point 

 shifting its position by miles every second, though 

 from the august magnitude of their distances from 

 us and from each other, it is only by the accumulated 

 movements of years or of generations that some small 

 changes of relative position reveal themselves. 



" The deciphering of this wonderfully intricate 

 constitution of the heavens will be undoubtedly one 

 of the chief astronomical works of the coming cen- 

 tury." * 



One interesting result as to method should be 

 noted, namely, the development of stellar photogra- 

 phy. When even the trained eye, with the telescope 

 to help, cannot detect, the photographic plate may 

 reveal. The invention and improvement of the gela- 



* Sir William Huggins. President's Address, Rep. Brit. 

 Ass. for 1891, pp. 35-36. 



