24 THE BORDERLAND OF SCIENCE. 



of milky light which have long been known by sailors 

 as the Magellanic Clouds, because Magellan was the 

 first voyager who recorded their existence. Astronomers, 

 however, usually call these objects the Nubeculce. Both 

 are nearly round, and their light, when they are viewed 

 with the unaided eye, corresponds exactly with that of 

 the Milky Way in regions of medium brightness. 



We owe to Sir John Herschel the first systematic 

 survey of these interesting objects. The result is full 

 of interest. In one respect telescopic scrutiny shows 

 that the Magellanic Clouds resemble the Milky Way 

 in constitution ; for scattered over both clouds are 

 myriads of stars of all magnitudes from the eighth 

 downwards. But also there are numbers of nebulae 

 within the limits of both clouds, whereas the ground 

 of the Milky Way is singularly free from true nebulae. 

 Nor are the nebulae in the Magellanic Clouds so spread 

 that we can attribute their appearance within the 

 limits of the clouds to accident, or judge their real 

 position to be (conceivably) far out in space beyond 

 the myriads of stars just referred to. On the contrary, 

 the space all round both the Magellanic Clouds is 

 singularly free as well from stars as from nebulae. To 

 use Sir John Herschel's own striking expression, ' the 

 access to the Nubeculae on all sides is through a desert.' 

 No doubt, then, can remain that the nebulae seen in 

 the Magellanic Clouds are within the same region of 

 space as the small stars seen along with them. 



Now let the reader carefully note the significance of 

 these facts. The reasoning by which that significance 



