Earth's Rocks to Meteorites. 231 



This likeness of the several grades of luminous meteors 

 has not been admitted by all scientific men. Especially it- 

 was not accejjted by your late President, Prof. J. Lawrence 

 Smith, who by his studies added so much to our knowledge 

 of the meteorites. 



The only objection of apparent force, that has been urged 

 against the relationship of meteorites and star-showers, is 

 the fact that no meteorites have been secured that are 

 known to have come from star-showers. Within the last 

 one hundred years there have been five or six star-showers 

 of considerable intensity, and the objection assumes that a 

 large number of stones must have come to the ground from 

 them, and have been picked up. But a reasonable estimate 

 of the total number of" meteors in all of these five or six 

 star-showers combined, makes it about equal to the number 

 of ordinary meteors which come into the air in six or eight 

 months, and the average annual number of stone-meteors of 

 known date, from which we have secured specimens, has 

 during this hundred years been about two and a half. 



Supposing the luminous meteors to be of the same origin 

 and astronomical nature, and that the proportion of those 

 fitted to come through the air without destruction is the 

 same among the star-shower meteors as among the other 

 meteors, a hundred years of experience would lead us to 

 expect two, or perhaps three, stone-falls, from which we 

 secure specimens during the half dozen showers put toge- 

 ther. To ask for more than two or three, is to demand of 

 star-shower meteors more than other meteors give us. The 

 failure to get these two or three may have resulted from 

 chance, or from some peculiarity in the nature of the rocks 

 of Biela's and Pempel's comets. 



It may be assumed, then, as reasonable, that the shooting- 

 stars and the stone-meteors, together with all the interme- 

 diate forms of fireballs, are like phenomena. What we know 

 about the one may with due caution be used to teach facts 

 about the other. From the mineral and physical nature of 

 the different meteorites, we may reason to the shooting 

 stars, and from facts established about the shooting stars 

 we may infer something about the origin and history of the 



