10 



Dri Huggins was enabled to state the true nature of the nebulae. 

 He rehabilitated the nebular hyp/othesis, which was first enunciated 

 by Kant, and which had fallen into disfavour owing to the 

 erroneous inferences of Lord Eosse from what he had seen in his 

 great reflecting telescope. 



A nebula is a shining mass of mist — the rudimentary stage 

 in the formation of a star. At first it is shapeless, but it contains 

 potentially the suns and planets of the future. When a nebula 

 presents a spiral form an advance has been made. A still further 

 advance is exhibited when the nebula exhibits a globular appearance. 

 Some of tlie more rudimentary of the nebulae show in the Spectro- 

 scope the lines of hydrogen and nitrogen. 



The Sun's distance from the earth is about 93 millions of miles, 

 and his bulk is so great that he is alile to influence the distant 

 stars ; a Centauri is at a distance of 200,000 times that of the 

 earth from the Sun, and yet, unless that star were moving in a 

 direct line at the rate of 200 miles an hour, it would be drawn 

 towards the Sun. 



Wlien the Sun is eclipsed, a bright halo is seen around it, 

 and this is called the " Corona." This is composed of meteoric or 

 nebular matter. Underlying the Corona, and closely covering the 

 bright surface of the Sun, is the " Chromosphere," which consists 

 of coloured glowing gas. The coloured projections from the Chro- 

 mosphere are known as the '' Prominences," they can readily be 

 seen by means of a spectroscope of considerable power. 



The general surface of the Sun is not of uniform brightness, 

 it appears to be mottled and dotted here and there with bright 

 portions which are called " Faculse," and dark portions which are 

 known as "Sun Spots." Sun spots are usually preceded by 

 faculse ; they travel, not on the equator, but to the north and 

 south of it, and they are not found near tlie poles. When a spot 

 is examined in the spectroscope, it is seen that the lines of 

 Fraunhofer broaden out, as if the dark centre of the spot were a 

 cooler portion than the Sun's surface. Some spots exhibit a rapid 

 movement of rotation; a solar cyclone with a velocity of 166 miles 

 per second has been witnessed. Not only is the earth travelling 

 round the Sun, but the Sun itself is moving, and carrying all his 



