AD])HKS>!<. Ivii 



Dr. Olmsted explained tlic tippearaucc oi' a point from wliich the lines of 

 flight of meteors seem to radiate, as being the perspective vanishing point of 

 their parallel or nearly parallel courses appearing to an observer on the 

 earth as it a})proachcs them. The nuifornaity of position of these radiant 

 points, the many corroborative observations on the direction, the distances, 

 and the velocities of these bodies, the circumstance that their paths intersect 

 the earth's orbit at certain definite periods, and the total failure of all other 

 theories Avhich have been advanced, -while there is no substantial objection to 

 this, afford evidence almost amoimting to proof that these are cosmical bodies 

 mo^-ing in the interplanetary space by gra\itatiou round the sun, and some 

 perhaps round planets. This view gives us a new element of continuity. 

 The universe -would thus appear not to have the extent of empty space 

 formerly attributed to it, but to be studded between the larger and more 

 A'isible masses with smaller planets, if the term be permitted to be applied to 

 meteorites. 



Observations are now made at the periods at which meteors appear in 

 greatest numbers— at Greenwich by Mr. Glaisher, at Cambridge by Prof. 

 Adams, and at Hawkhiu'st by Mr. Alexander Herschel — and every preparation 

 is made to secure as much accuracy as can, in the present state of knowledge, 

 be secui-ed for such observations. 



The number of kno-wn asteroids, or bodies of a smaller size than what are 

 tenned the ancient planets, has been so increased by numerous discoveries, 

 that instead of seven we now count eighty-eight as the number of recognized 

 planets — a field of discovery with which tlie name of Hind ■v\'ill be ever 

 associated. 



If we add these, the smallest of which is only twenty or thirty mUes in 

 diameter, indeed cannot be accurately measured, and if we -\\'ero to apply the 

 same scrutiny to other parts of the heavens as has been applied to tlie zone 

 between Mars and Jupiter, it is no far-fetched speculation to suppose that 

 in addition to asteroids and meteorites, many other bodies exist until the 

 space occupied by our solar system becomes fiUed np with planetary bodies 

 varying in size from that of Jupiter (1240 times larger in volume than the 

 earth) to that of a cannon-ball or even a pistol-buUct. 



The researches of Leverrier on the iutra-mcrcurial planets come in aid of 

 these views ; and another half century may, and not improbably will, enable 

 us to ascertain that the now seemingly vacant interplanetary spaces are 

 occupied by smaller bodies which have hitherto escaped observation, just as 

 the asteroids had nntil the time of Olbers and Piazzi. Put the evidence of 

 continuity as pervading the universe does not stop at telescopic observation ; 

 chemistry and physical optics bring usnewproofs. Those meteoricl)odies which 

 have from time to time come so far -v^-ithin reach of the earth's attraction as 

 to fall iipon its surface, give on analysis metals and oxides similar to those 

 which belong to the structure of the earth— they come as travellers bringing 

 specimens of minerals from extra-terrestrial regions. 



In a series of papers recently communicated to the French Academy, 

 M. Daubree has discussed the chemical and raincralogical character of 

 meteorites as compared with the rocks of the earth. He finds that the 

 similarity of terrestrial rocks to meteorites increases as we penetrate deeper 

 into the earth's crust, and that some of the deep-seated minerals have a 

 composition and characteristics almost identical with meteorites [olivine, 

 herzolite, and serpentine, for instance, closely resemble them] ; that as we 

 approach tlie surface, rocks having similar components with meteorites are 

 found, but in a state of oxidation, which necessarily much modifies their 



