212 IN STARRY REALMS. 



aspects of the same object obtained from widely different 

 points of view. It is, in fact, the very difference between 

 these positions which renders it possible to discover the 

 true situation of the luminous streak. 



The point at which the meteor appeared to vanish from 

 Bristol was at an elevation of nearly 30, a little to the 

 west of north. Lay, therefore, a map of England on the 

 table, fasten with a pin a piece of thread at Bristol, and 

 then stretch the thread up towards the north at an inclina- 

 tion of one- third of a right angle above the surface of the 

 map. The observation at Bristol then assures us that the 

 vanishing point of the meteor was somewhere along that 

 line. The observation at Leeds tells us that the vanishing 

 point of the meteor was towards the south- west. A little 

 study of the map shows us that the line of sight from 

 Bristol to the meteor passes nearly over Chester, and that 

 Chester is south-west from Leeds. Hence we see that the 

 vanishing point must have been directly over Chester, 

 and the slope of the incline from Bristol indicates that the 

 height of the meteor must there have been about sixty 

 miles. If any inhabitant of Chester were fortunate enough 

 to have noticed that bright meteor he would apparently 

 have seen it terminate at a point exactly over his head. 



The terminal point of the meteor is usually much better 

 observed than the initial point. Nor is this a matter for 

 surprise. The attention of an observer is often directed 

 towards the object by a bright light, while he may be 

 looking in quite another direction. He turns round and, 

 of course, follows the glorious object to its close at a point 

 the situation of which he can note accurately. It seems 

 in this case that the meteor was observed at a much earlier 



