THE SIDEREAL UNIVERSE. 703 



The nebula of the Bull shows like a luminous body length- 

 ened out, from which project claw-like appendages formed 

 by long trains of stars. Struck with its appearance, Lord 

 Rosse, when he saw it for the first time through his im- 



254. Spiral Nebula of the Constellation of the Greyhounds ( Canes Venatici). 



mense telescope, gave it the name of the Crab nebula, an 

 animal of which its singular form puts one in mind. 



The nebulae mark the limits of sidereal investigation. In 

 proportion as with our new means we extend our researches 

 further into the starry sphere, we find new luminous bodies 



