1 68 LIGHT SCIENCE FOR LEISURE HOURS. 



' Astronomy has satisfactorily proved,' he says, * that 

 there are meteors enough in the solar system to 

 produce the corona ; and we all know that this coronal 

 light is never concentric with the sun, and that it 

 generally runs out in particular directions, and is never 

 seen twice in the same form. Almost every drawing 

 or photograph taken in eclipses proves that it is much 

 brighter in some parts than in others, that is, that the 

 matter which reflects the sunlight is not uniformly 

 dense, and stops and reflects more of the sunlight 

 proceeding in certain directions than in others; and 

 any planet placed, so to speak, behind an expansion of 

 the corona would suffer loss of light. If this coronal 

 point (or projection) be, as they sometimes are, of 

 enormous extent, there must be a corresponding loss 

 of light and heat, and to such variations of sunlight 

 the earth is beyond question subjected. There are 

 hundreds of meteor systems cut by the earth's orbit 

 which, as they all pass round the sun, must be concen- 

 trated (in his neighbourhood), and hence it is more 

 than probable that when we look at an eclipse, there 

 is just as great an extension of the corona towards the 

 earth, where we cannot see it, as we see to right and 

 left of our line of sight. Unfortunately, suitable 

 eclipses come so seldom that the recurring forms of 

 corona, which the fall of temperature in February, 

 May, and at other dates seems to indicate, cannot be 

 seen; but we know that the meteor streams have 

 definite orbits about the sun; and therefore would 

 place each year about the same quantity of meteoric 



