DEATH BY LIGHTNING. 399 



been able to testify that no pain was felt prior to the loss 

 of consciousness. 



The time required for a rifle-bullet to pass clean through 

 a man's head may be roughly estimated at a thousandth of 

 a second. Here, therefore, we should have no room for 

 sensation, and death would be painless. But there are 

 other actions which far transcend in rapidity that of the 

 rifle-bullet. A flash of lightning cleaves a cloud, appearing 

 and disappearing in less than a hundred-thousandth of a 

 second, and the velocity of electricity is such as would carry 

 it in a single second over a distance almost equal to that 

 which separates the earth and moon. It is well known 

 that a luminous impression once made upon the retina en- 

 dures for about one-sixth of a second, and that this is the 

 reason why we see a ribbon of light when a glowing coal 

 is caused to pass rapidly through the air. A body illumi- 

 nated by an instantaneous flash continues to be seen for the 

 sixth of a second after the flash has become extinct ; and 

 if the body thus illuminated be in motion, it appears at 

 rest at the place where the flash falls upon it. The color- 

 top is familiar to most of us. By this instrument a disk 

 with differently-colored sectors is caused to rotate rapidly ; 

 the colors blend together, and, if they are chosen in the 

 proper proportions, when the motion is sufficiently rapid 

 the disk appears white. Such a top, rotating in a dark room 

 and illuminated by an electric spark, appears motionless, 

 each distinct color being clearly seen. Professor Dove has 

 found that a flash of lightning produces the same effect. 

 During a thunder-storm he put a color-top in exceedingly 

 rapid motion, and found that every flash revealed the top 

 as a motionless object with its colors distinct. If illuminated 

 solely by a flash of lightning, the motion of all bodies on 

 the earth's surface would, as Dove has remarked, appear 

 suspended. A cannon-ball, for example, would have its 

 flight apparently arrested, and would seem to hang motion- 



