228 Canadian Record of Science. 



These elevations and submergences of the plateaus alternated 

 with the periods of mountain-making plication, which was 

 going on at intervals at the close of the Eozoic, at the begin- 

 ning of the Cambrian, at the close of the Siluro-Cambrian, 

 and in Europe and "Western America in the Tertiary. The 

 series of changes, however, affecting all these areas was of 

 a highly complex character, and embraces the whole physi- 

 cal history of the geological ages. 



We may here note that the unconformities caused by these 

 movements and by subsequent denudation constitute what 

 Le Conte has called ' lost intervals,' and one of the most im- 

 portant of which is supposed to have occurred at the end of 

 the Eozoic. It is to be observed, however, that as every 

 such movement is followed by a gradual subsidence, the 

 seeming loss is caused merely by the overlapping of the 

 successive beds deposited. 



{To be Continued.) 



Relations op the Earth's Rocks to Meteorites. 



By H. A. Newton, 

 Retiring President of the American Association for the Advancement of Science. 



[abstract.] 



After briefly recounting the various superstitions and 

 popular views respecting the origin of meteorites and their 

 influence upon the earth, the President reviewed the 

 various views advanced by scientists and reduced them to 

 the following generally accepted propositions : — 



1. The luminous meteor tracks are in the upper part of 

 the earth's atmosphere. Few meteors, if any, appear at a 

 height greater than one hundred miles, and few are seen 

 below a height of thirty miles from the earth's surface, 

 except in rare cases, when stones and irons fall to the 

 ground. All these meteor tracks are caused by bodies 

 which come into the air from without. 



2. The velocities of the meteors in the air are compar- 

 able with that of 'the earth in its orbit about the sun. It is 

 not easy to determine the exact values of those velocities, yet 

 they may be roughly stated as from fifty to two hundred and 



