METEORS. 145 



catalogue of meteoric radiants, containing 436*7 ; 

 and he has carefully studied the remarkable 

 objects known as fireballs or " sporadic meteors." 

 He has occasionally been able to trace a con- 

 nection between fireballs and weak meteoric 

 showers, but he concludes that they " must 

 either be merely single sporadic bodies, or else 

 the survivors of some meteor group, nearly 

 exhausted by the waste of its material during 

 many past ages." All of Denning's meteoric 

 work has been done in his spare time, for it 

 must be borne in mind that he pursues the 

 profession of accountant in Bristol, and that 

 only his leisure hours have been devoted to 

 the science of astronomy. His researches have 

 been entirely conducted with the unaided eye. 

 His only instrument is a perfectly straight 

 wand, which he uses as a help and corrective 

 to the eye in ascribing the paths of the meteors. 

 Thanks to the laborious work of this able 

 English astronomer, the observation of meteors 

 is now a scientific branch of astronomy. In 

 the words of Maunder, " for six thousand years 

 men stared at meteors and learned nothing, for 

 sixty years they have studied them and learned 

 much, and half of what we know has been 

 taught us in half that time by the efforts of 

 a single observer." 



K 



