687 ™~ 
the introduction of glacial action among geological dynamics, the 
fundamental principles of our science remain entirely unaffected. 
Conspicuous as it may appear through the attractive descriptions of 
Agassiz, or the eloquence of Buckland, the glacial theory must be 
considered an episode only in the records we are labouring to pre- 
pare of the grand changes of the planet. Let not, therefore, geology 
be decried as a science without fixed principles, because her culti- 
vators have recently differed upon a point which, though connected in 
theory with the science, has no bearing whatever on its uses nor upon 
the many fundamental points which it had previously established. 
Your labours, Gentlemen, and those of your foreign associates, 
have already afforded proofs of the regular succession of the strata, 
and have traced their chronology ; you have accurately marked the 
revolutions which have interrupted the sequence of by-gone races; 
you have explained the origin and position of various mineral sub- 
stances essential to mankind, the dependence of geographical and 
agricultural products upon geological laws, and have shown how 
antagonist forces proceeding from the interior have modified the 
earth’s outline, and been the cause of mineral wealth,—in a word, 
by your patient study of the masses you have acquired a true know- 
ledge of the structure of the surface of the globe. 
By these achievements the geologist has earned his best trophies, 
and has shown that the principles of his science are based upon the 
unerring laws of nature. Let then the shortness of his bright ca- 
reer incite us to renewed exertions, so that if at the close of life our 
vast subject should still present some unexplained phenomena, we 
may at all events have won the race in our own generation by esta- 
blishing new landmarks in the rapidly increasing delta of natural 
knowledge. 
