278 THE WORLD MACHINE 



was to lead to something more than a striking exhibit of the 

 powers of calculation. The bombardment of the earth by the 

 meteorites is incessant ; we see them, of course, only at night ; 

 but the hail of these bodies, large and small, continues through 

 the day as well. One careful series of counts was made which 

 indicated that the number may reach fifty or sixty thousand 

 in each twenty-four hours, perhaps twenty millions in a year. 

 Most of them, of course, are very small. Taking an average, 

 Professor Newton, who virtually created the modern view of 

 meteorites, calculated that the earth in its flight sweeps up a 

 hundred, or it may be several hundreds of tons of meteoric 

 matter per day. It is not a great deal, perhaps, set against 

 the vast bulk of the globe. In a million years, perhaps, they 

 would not at this rate cover the whole surface of the earth 

 with a layer more than an inch thick. But their number pro- 

 bably is growing less year by year ; it may have been far greater 

 in the long ago. If we prolong our vision far backward, through 

 geologic time, through hundreds of millions of years, we see 

 that the cumulative effect must have been great. 



Moreover, just as the comets and meteoric swarms may be 

 pulled apart, disintegrated by large bodies, so evidently they 

 may come together, may coalesce, may be integrated among 

 themselves. Instantly in the reflecting mind comes the ques- 

 tion : is it from these that worlds are born ; is it thus that through 

 the aeons, suns and planets grow ? Though such an idea has 

 come to more than one mind, it remains as yet rather an in- 

 teresting possibility than a tenable theory. 



Step by step the mystery slips away. With the terror of 

 the comets a large part of it had gone ; not all. Back in 

 Newton's and in Halley's time there was one they must have 

 pondered oft. It brought no terror ; it was a puzzle none the 

 less. What is light ? Does the effulgence of the sun, the 

 radiance of the stars, flash to us in no lapse of time ? Can its 

 traverse of space be instantaneous ? 



So it seemed. And yet the fact was unthinkable, just as 

 the fact of gravitation is still. Already one young observer had 

 seen that some curious appearances could not be so explained. 

 Until the matter was cleared up, certain avenues to investigation 

 were blocked. Science cannot deal with infinities. The path 

 to the solution was devious. 



