8 Notes on Star- Streams. 



of nebulous light in the background, it is obvious that the two 

 streams are not absolutely coincident in direction. The stream 

 lies (in the figure) above the Milky Way near Scorpio, crosses 

 it in the neighbourhood of Crux, and passes below it along 

 Canis Minor, Orion, and Taurus. Does the stream return to 

 the Milky Way ? It seems to me that there is clear evidence 

 of a separation near Aldebarau, one branch curving through 

 Auriga, Perseus, and Cassiopeia, the other proceeding (more 

 nearly in the direction originally observed) through Aries 

 (throwing out an outlier along the band of Pisces), over the 

 square of Pegasus, and along the streams which the ancients 

 compared to water from the urn of Aquarius (but which in our 

 modern maps are divided between Aquarius and Grus). The 

 stream-formation here is Yery marked, as is evident from the 

 phenomenon having attracted the notice of astronomers so 

 long ago. But modern travels have brought within our ken 

 the continuation of the stream over Toucan, Hydrus, and Eeti- 

 culum (the two latter names being doubtless suggested by the 

 convolutions of the stream in this neighbourhood). Here the 

 stream seems to end in a sort of double loop, and. it is not a 

 little remarkable that the Nubecula Major lies within one loop, 

 the Nubecula Minor within the other. It is also noteworthy 

 that from the foot of Orion there is another remarkable stream 

 of stars, recognised by the ancients under the name of the 

 River Eridanus, which proceeds in a sinuous course towards 

 this same region of the Nubeculas. 



Having thus met with evidence — striking at least, if not 

 decisive, — of a tendency to aggregation into streams, let us con- 

 sider if, in other parts of the heavens, similar traces may not 

 be observable. We traced a stream from Scorpio towards Orion, 

 and so round in a spiral to the Nubeculas. Let us now return to 

 Scorpio, and trace the stream (if any appear) in the contrary 

 direction. Now although over the northern hemisphere star- 

 streams are not nearly so marked as over the southern, yet 

 there appears a decided indication of stream-formation along 

 Serpens and Corona over the group on the left hand of Bootes 

 to the Great Bear. A branch of this stream, starting from 

 Corona, traverses the body of Bootes, Berenice's Hair, the 

 Sickle in Leo, the Beehive in Cancer, passing over Castor and 

 Pollux in Gemini, towards Capella. A branch from the feet of 

 Gemini passes over Canis Minor, along Hydra (so named 

 doubtless from the obvious tendency to stream-formation along 

 the length of this constellation), and so to the right claw of 

 Scorpio. Four small stars of Hydrus are indicated in Fig. 2 

 between Scorpio and Centaurus near the upper edge of the 

 figure. 



One other remarkable congeries of stars is to be mentioned. 



