222 LIGHT SCIENCE FOR LEISURE HOURS. 



tion. A curious observation to be recorded, sent to 

 some learned society, and forgotten ? Not altogether so. 

 Olmsted had a brain, as well as eyes wherewith to observe, 

 and he reasoned that 'such an independence of the 

 earth's rotation shows that the luminous body must have 

 reached our atmosphere from without.'' A fanciful 

 theory, truly, said in effect the mere observers, for they 

 proceeded to speak of meteors as though nothing of 

 the kind had been shown. The fact is, however, they 

 were to be excused : Olmsted's reasoning was demon- 

 strative only for those who could follow him ; he could 

 give reasons, he could not give understanding. 



So also, the occurrence of showers on particular 

 days of the year that is, at times when the earth is 

 in particular parts of her orbit round the sun was re- 

 cognised by reasoning men as proof positive that meteor 

 systems are extra-terrestrial. Humboldt, though he 

 was not, properly speaking, an astronomer, yet studying 

 astronomy like other sciences, with care to obtain an 

 insight into the facts, saw the real meaning of this 

 particular fact. 



Now, of course, what was proved half a century ago 

 by Olmsted, Encke, and others, is the accepted teach- 

 ing of science. The August shooting stars gave the 

 first obvious and easily understood evidence on the 

 subject. When it was noticed that the larger comet of 

 1862 crossed the earth's track where the August 

 meteors are encountered, every one could understand 

 what Schiaparelli meant when he said that bodies fol- 

 lowing in the track of that comet would appear (as 



