

THE NATIONAL GEOGRAPHIC MAGAZINE 



Photograph from Yerkes Observatory 



one op the; spiral nebui^ 



This wonderful mass of whirling matter is at about the center of a circle that would be 

 made by the continuation of the arc which forms the curve of the handle of the Big Dipper. 

 One of the same type — the great Andromeda Nebula — is said to be approaching the earth at 

 the wonderful speed of 12,000 miles a minute. Astronomers generally hold that of such 

 whirling masses as these are worlds created (see page 177). 



bound up, as a star, to the other stars 

 by influences reaching across the un- 

 imaginable void that separates them." 



A TERRIFYING PACE 



Spectroscopic studies and sky observa- 

 tion alike tell us that our sun and his 

 family arc all headed in a great migra- 

 tion across the sky toward a point be- 



tween the constellations of Hercules and 

 Lyra (see picture, page 177). 



The speed with which we are travel- 

 ing in that direction is twelve miles a 

 second. The velocity of an artillery 

 shell is around 3,000 feet a second; that 

 of the sun 63,000 feet. An artillery shell 

 with the velocity of the solar system 

 through space would, according to Kip- 



