Colours of Stars — Clusters and Nebulce. 115 



telescope, and Arago expresses an opinion that among the 

 sixty or eighty thousand isolated stars which have been cata- 

 logued, no other designations except white, red, and yellow 

 are to be found. Here we seem to trace the existence of some 

 unknown general law. Again, it may be remarked that stars 

 of a deep fiery aspect, or even a ruby or actually sanguine hue, 

 are not very uncommon, while an equal intensity in green or 

 blue is scarcely to be met with. These crimson or sanguine 

 stars, however, do not attain any conspicuous brightness ; and 

 it is doubtful whether this can be accounted for on the general 

 principles of average distribution, as their whole number is not 

 great, or whether it may be connected in some occult way with 

 actual size. At any rate, no instance, so far as I am aware, 

 of crimson light occurs among the multitude of stars above the 

 8th magnitude ; Herschel I/s " garnet star " (/£ Cephei, 6 mag., 

 variable), by no means answering the description. Antares, 

 the leader of the ruddy class, shows little more than a rosy 

 orange ; Aldebaran, Betelgeuse, and others are still less intense. 

 Another curious fact is, that such sanguine stars are, without 

 exception, so far as is hitherto known, insulated — no doubt a 

 significant fact, could its interpretation be only found. And 

 so probably is that mentioned by Herschel II., that it is no 

 uncommon thing to find a very red star much brighter than 

 the rest, occupying a conspicuous situation in a cluster ; and 

 that described by Secchi, that among the spiral curves, or 

 radiating figures, in which the larger galactic stars are so mar- 

 vellously arranged, there is usually in the centre of the radia- 

 tion, or at the starting-point of the spiral, a redder as well as 

 larger star. ' ' II est impossible de croire que telle distribution 

 soit accidentelle.'" And still more convincingly must this con- 

 clusion be drawn, when closely aggregated nebulae exhibit a 

 general blue light pervading all their constituents, or when a 

 rich globular cluster is all of a pale rose tint, within a concen- 

 tric border of minute white stars. Here it would be blindness 

 indeed not to acknowledge the presence of some law, not the 

 less real, because at present it escapes our grasp, or because 

 the development of it may possibly be reserved for a future 

 state of existence. 



CLTJSTEES AND NEBULiE. 



The earlier closing in of our evenings renders it now 

 pleasant as well as practicable to return to the search after 

 objects requiring a dark background, and, before it sinks too 

 low, we will begin with — 



19. The Cluster in Sobieski's Shield. I venture to call it 

 so, because — though according to our standard authority, the 

 Bedford Catalogue, it belongs to the constellation Antinous — it 



VOL. VI. — NO. IT. I 



