MIRACLES OF SCIENCE 



gravitational effect, are believed to be practically in 

 contact. This supposition does not do violence to the 

 rule of Roche's limit, which prohibits solid bodies to 

 maintain such close contiguity, for the calculations 

 show that these stars, notwithstanding their enor- 

 mous mass, have an average density less than that 

 of air at sea level. Beta Lyrae is therefore in effect 

 a double nebula; but to the mundane observer it 

 appears as a single point of light. 



Not far from this star there is a nebula of vastly 

 greater proportions which belongs to the small group 

 of ringed nebluae and is the only one of its class that 

 may be seen through a small telescope. The interest- 

 ing peculiarities of this nebula are brought out to 

 advantage only by the largest instruments, but the 

 amateur will find it well worth inspection even with 

 a three-inch glass. 



The central star in this nebular ring suggests that 

 a gigantic solar system is here in process of construc- 

 tion. The ring may represent a mass of nebular mat- 

 ter that has failed to aggregate into a planet through 

 lack of a nucleus of condensation. 



