206 Dana and Chambers on Ancient Sea- Margins. 



were first noticed ; yet hitherto only isolated cases, or parti- 

 cular valleys have received much attention. Mr Chambers 

 is the first who has collected together the various observa- 

 tions, and from these and other results of his own, has endea- 

 voured to arrive at a general deduction for the whole. He 

 concludes that those of different countries point, in many in- 

 stances, to a single cause, operating simultaneously over 

 distant regions. He observes : — 



** There is nevertheless enough to justify a question regarding unifor- 

 mity of level, not only throughout North America, but also — bold as the 

 idea, in the present state of knowledge and of hypothesis, may appear — 

 between the old and the uqw continents. It has certainly appeared to 

 myself, to say the least, as a promising prognostic of some important new 

 views regarding a chapter in the past history of the globe, when, it be- 

 ing granted that terraces and benches of land are marks of ancient levels 

 of the sea, I find that a tendency to a bench form or plateau, at 60, or 

 from 60 to 70 feet above present high water, exists on the coasts of the 

 United States and in the Gulf of St Lawrence, as it does in Britain ; that 

 conspicuous terraces in Britain and in France at 188 and 392 feet are 

 repeated in America ; that there, also, at about 545 feet, are several re- 

 petitions of a decided and most notable Scottish terrace — that Scott built 

 his house of Abbots ford on an ancient sea-beach beside the Tweed, which 

 finds an analogue in the first of the grand ridges sweeping from east to 

 west behind Toronto ; and that the sandy plateaux of Lanark and Car- 

 stairs are in metrical harmony with the terraces and ridges of the half- 

 peopled wilds of Michigan." — P. 316. 



This must be viewed as a bold inference, and should not 

 be admitted without extended investigation. It is certainly 

 a legitimate subject of enquiry, and one of the grandest in its 

 range, before the geologist. If proved, it declares that the 

 causes of variation in the water-line, in the recent history of 

 the globe, have acted at certain periods as widely as the 

 ocean. If disproved, the facts indicate changes no less ex- 

 tensive, which have been produced at different epochs for 

 different regions, and they shew a still greater instability in 

 the earth's surface, telling of oscillations in its various parts 

 continued through ages since the tertiary epoch, until a whole 

 continent has been terraced in all its valleys.* 



* In connection with the subject of Terraces, we add a remark here on the 



