Knowledge. 



With which is incorporated Hardwiclie's Science Gossip, and the Ilkistrated Scientific News. 



A Monthly Record of Science. 



Conducted by \\'ilfred Mark Webb, F.L.S., and E. S. Grew. .M.A. 



XO\EMBER, lyil. 



THE NEW ASTRONOMY. 



III.-ST.AR CLUSTERS AXD NEBULAE. 



By PROFESSOR A. W. BICRICRTOX. 



W'itli aiiistratioiis from photographs by G. 11'. Ritchcy. 



It seems Strange that astronom\-, with all the mar\els when star clusters are seen throu,i;h i^iant telescopes, 



the\' appear to eclipse evervthing else for brilliant 



re\ealed b\- the modern methods, has not a greater 

 hold on the human mind. But doubtless the wondrous 

 beautv of the heavens appeals far more to a shepherd 

 folk, w ith their ample night leisure, their clear sky, 

 their serene minds, than to city peojile. The 

 brilliantlv lighted streets of London outshine even 

 Sirius or the brightest comet. I have seen the moon 

 herself showing over the house tops as a feeble kind of 

 large artificial light. In a big city, music hall stars 

 are far more effecti\"el\' attractive than a shining star 

 cluster or even the whole gala.xy of the heavens. 

 Astronom\- too, has become somewhat drv and arid. 

 Official astronomers do not care for theories, for the 

 linking silken cords of correllation, that will weave 

 together their wonderful isolated threads of facts 

 and convert them into the shimmering fabric of a 

 beautiful and consistent scheme of creation so grand 

 and glorious as to be capable of giving hope and 

 energ\- to human thought, and high purpose to human 

 aims. Nevertheless the neglected celestial vault is the 

 stage of much romance and beauty. The moon under 

 a telescope of moderate power is an exquisite object, 

 and so is the crescent of \enus. the ringed planet 

 Saturn, or the spiral nebulae. But perhaps, as I 

 said in Harper's .Ma<>aziiu', Se[)tember number, 

 imagination is wanted : "■ Were we to picture time as 

 passing so swiftly that centuries were as seconds, to 

 the eye of the mind we should see the star clusters 

 appearing as moving masses of manv-hued fireflies, 

 the planets as rings of silver light, and we sliould 

 see the whole stellar heavens astir as a swarm of 

 shining bees." No imagination seems to be required 



magnificence. 



The Wundkk and Bkautv uf Star 

 Clusters. 



These groups of celestial gems may sparkle like 

 diamonds of the first water, or they may shine 

 with man\- a \aried tint, some blue be\'ond the 

 Oriental sapphire, some vivid green, or red, or purple. 

 Some of the groups are all white : some, as in the 

 constellation of the Southern Cross, are white, 

 interspersed with red. blue, and green stars : while 

 the most wonderful of all the clusters, that in the 

 Toucan, is of an exquisite rose tint. Then the 

 number of component stars is wonderful : in most 

 clusters they may be counted by hundreds, in some 

 there are manv thousand independent points of light, 

 everv point of light a sun perchance bearing a 

 planetar_\- s\-stem with it. \MTat possibilities unfold 

 themselves. Think of an\' one of those solar s\stems 

 threading its w ay through the ma^e of the other suns. 

 What vicissitudes it must encounter. For hundreds 

 of vears it might revolve amongst the densities at 

 the centre of the svstem : then its orbit might be 

 deflected and for thousands of years it might travel 

 towards the exterior of the cluster. With the 

 sudden effect of natural selection, on the satellites 

 of such a sun, the changes from tropic to arctic 

 diu-ing the great glacial epochs of the earth would 

 hardh" compare. Then, again, how the hea\ens must 

 alter in aspect within those wondrous coloured 

 clusters, where in one part the emerald and the 



413 



