70 



Tvith, the majority of them would be kindled into flame by- 

 friction against its atmosphere. Yon have all of you seen such 

 phenomena, and you have spoken of it as that of falling or 

 shooting stars. These too, as you are aware, come sometimes in 

 showers. 



Every August and November, and April, the earth passes 

 through huge shoals of such moving particles, as they pass 

 onward in their revolution round the sun. Every 33 year,9 

 a swarm of meteoric bodies crosses the orbit of the earth, and 

 then the sight is not easily forgotten. Some of you may, 

 perhaps, remember the night of the 14th of November, 1867. 

 Those who do not will see but a poor picture of its splendours 

 in the one now on the screen. The earth then passed through 

 ^hat great system of meteors which must have been at least one 

 thousand millions of miles in length, and probably a million 

 miles in width. You begin perhaps to suspect that there is 

 a closer connection between shooting stars and comets than you 

 had anticipated. And, truly, the discovery of the relation 

 between them is one of the great glories of the astronomical 

 research of the last few years. It has long been known that 

 these meteor-systems travelled in very eccentric orbits, just as 

 comets do, but it was left for Professor Schiaparelli, of Milan, to 

 show conclusively that the elements of the orbits of two comets, 

 Biela's and Temprel's, were almost absolutely identical. 



The exact relation between comets and these streams of 

 cosmic dust is not established with precision, but they are so 

 intimately associated that we may regard these showers of 

 meteors as at least the dissociated granules of that which was 

 once a comet. Astronomers have determined the paths of more 

 than one hundred meteor systems. It has been calculated that 

 more than seven millions of shooting stars or meteors dash into 

 the earth's atmosphere every twenty-four hours. The lowest 

 computation that I have seen puts the comets which belong to 

 our solar system, that circle round our sun, at seventeen millions. 



