2i8 IN STARRY REALMS. 



quently told that even the beams of the full moon are 

 ineffectual in comparison with the blaze of the meteor ; 

 and we find a high authority asserting that one of these 

 bodies displayed a flash as " blinding as the sun." But 

 our knowledge of the actual illuminating power of meteors 

 is almost unavoidably of rather an inaccurate description. 

 We could measure the light, no doubt, with all practical 

 precision if we knew when and where to expect it, for 

 then we could bring a suitable photometric apparatus to 

 bear at the critical moment. In the absence of any pre- 

 cise information, we are forced to make the most of such 

 occasional comparisons as may be available. On the 29th 

 July, 1878, a fire-ball was seen which created so splendid 

 an illumination that " the smallest objects were visible at 

 Manchester." An eye-witness states that when at its best 

 the fire-ball had the lustre of a powerful electric light seen 

 from a distance of thirty or forty yards, though at the 

 moment the fire-ball must certainly have been forty-five 

 miles away. We can make a comparative estimate of the 

 intrinsic intensity of a light which, when received from a 

 distance of forty-five miles, has a brilliancy equal to that 

 of a known source thirty-five yards away. It is thus 

 shown that the fire-ball must have emitted more light 

 than five million electric lamps. 



Fortunate indeed would the astronomer have been who, 

 guided by some miraculous prescience, had gone to the 

 ancient city of York on the evening of the 23rd of Feb- 

 ruary, 1879, and on the tower of the glorious minster 

 spent the night in observation of the heavens. It would 

 have been his privilege to witness a majestic meteor under 

 circumstances of almost unique magnificence. 



