938 ANNUAL REGISTER, 1809. 



geology, can be furnished only by 

 travels, made for the express pur- 

 pose of observation. 



" At the first glance, however, 

 we seem to be here replunged into 

 that confusion of objects, pre- 

 sented to our view by nature her- 

 self; for we find, in the same 

 places, phenomena which may be 

 assigned to different periods of the 

 history of the earth ; and it is by 

 the different judgments formed re- 

 specting those periods, that the 

 contrariety between geological 

 theories has been chiefly produced, 

 and is still maintained. From this 

 consideration, I was at first under 

 some difficulty, with regard to the 

 form which 1 should give to the 

 relation of my travels. For, if to 

 prevent this confusion of periods, 

 I had been obliged to interrupt my 

 account of every place, in order to 

 point out the different characters 

 of the objects there found toge- 

 ther, and to what different times, 

 notwithstanding their present union, 

 they ought respectively to be 

 referred, I should have fallen into 

 a tediousness, equally fatiguing to 

 my readers and to myself. And 

 if, to avoid that inconvenience, I 

 had abridged my descriptions, I 

 should have acted in direct opposi- 

 tion to my own views ; since it is 

 only by the accumulation of parti- 

 cular phenomena, always the same 

 under the same circumstances, that 

 an exact generalization of each 

 class of phenomena can be ob- 

 tained. 



" These considerations have led 

 me, as the means of avoiding com- 

 ments continually repeated on the 

 objects successively observed, to 

 arrange, at the beginning, under 

 certain heads, the points which are 



to be proved by each class of phe- 

 nomena. From such a definition 

 of the characters of these points, 

 the particular phenomena respec- 

 tively belonging to them may be 

 easily distinguished, wherever, in 

 the course of the descriptions, they 

 shall occur. 



" This plan, of giving at first a 

 general view both of the points 

 which are to be proved by facts, 

 and of the manner in which facts 

 are to effect the proof, will cer- 

 tainly require constant attention 

 from my readers ; but to what 

 science is not attention necessary? 

 If this method be duly considered, 

 it will, I hope, be allowed, that, 

 provided the facts generalized un- 

 der each head be certified by the 

 whole assemblage of the descrip- 

 tions which respectively concern 

 them, all the conclusions thence 

 deduced are incontestible. This, 

 then, is what must be constantly 

 kept in view ; since, when the 

 importance of these different heads 

 shall have been sufficiently consi- 

 dered, and the heads themselves 

 committed to memory, each of 

 them, by a sort of affinity, will 

 attract to itself those phenomena, 

 which properly belong to it, with- 

 out interruption of the course of 

 my observations, for the purpose 

 of pointing out such relations 

 wherever they occur. 



" There is one theoretical point, 

 of which I have treated at consider- 

 able length in my late work, but 

 which I must again introduce here 

 in a formal manner, on account of 

 its fundamental importance in the 

 history of the earth. It consists 

 in the following question : ' Can 

 the state of our continents at their 

 birth be certainly determined T 



•« The 



