8 OUTLINES OF NATURAL PHILOSOPHY. 



light, and of an irregular shape, are discovered ; 

 and on applying to them telescopes of great 

 power, they are resolved into a multitude of 

 small stars, distinctly separate, but extremely 

 near to one another. These are called Nebulae. 



a. The Milky Way is a space of this kind, visible to 

 the naked eye, and encompassing the whole hea- 

 vens. DR HERSCHEL'S telescope discovers it to 

 consist of a vast multitude of stars, ( 31. d}. 



Other two nebula near the South Pole, distinguish- 

 able by the naked eye, are called by sailors the 

 Magellanic Clouds. The telescope shews them 

 also to be composed of stars. 



b. The other nebula are not visible but with tele- 

 scopes. HUYGENS discovered one in Orion's 

 Sword, that appeared a bright spot on a dark 

 ground, and seemed like an opening into some 

 brighter region. 



c. Several more nebula had been observed before Dr 

 HERSCHEL, by HALLEY, CASSINI, LA CAILLE, &c. 

 and a catalogue of 103 was published by the French 

 astronomers, in the Connaissance des Terns for 

 1783. Dr HERSCHEL has given a catalogue of 

 more than 2000 discovered by himself. Phil. 

 Trans. 1786, 1789, &c. 



38. Dr HERSCHEL has also discovered nebu- 

 lous stars, that is, single stars, surrounded by a 



faint 



