PEEFAGE. XIX 



have not been identified, they being hidden either by the waters of the 

 bay or by the drift covering which conceals the greater part of the surface 

 of the islands. Nevertheless, as Dr. Foerste, who has given much time 

 to the problem, remains convinced as to the distinct nature of this series, 

 it is proper that he should express his convictions in his portion of the 

 report. The matter is cleai'ly debatable, with the probability that the 

 truth is on the side of the observer who has the closest personal familiarity 

 with the field. 



It may here be observed that the conclusions of this report, so far as 

 they relate to the general structure of the basin of which it treats, are 

 most novel in the matter pertaining to the orogenic history of the field. 

 The judgment as to the nature of the mountain-building work rests in part 

 upon observations — in the main unpublished — which I have made in other 

 somewhat similar basins that lie along the Atlantic coast from Newfound- 

 land to North Carolina. The general proposition that the basins are char- 

 acteristically old river valleys which have been depressed below the sea 

 level, filled with sediments — the sedimentation increasing the depth of the 

 depression — and afterwards corrugated by the mountain-building forces, 

 will derive its verification in part, if at all, from study of other troughs of 

 the Atlantic coast. It may, however, fairly be claimed that the facts set 

 forth in this memoir show that this succession of actions has taken place 

 in the Narragansett field. 



The contributions to our knowledge respecting the value of the coal 

 deposits of this basin are not so great as might well be expected from a 

 careful study of the field. The truth is that the exploitation of the coal 

 beds has been done in an extremely blundering manner, so that, while a 

 large amount of money has been expended during the last hundred years, 

 the amount of information which has come from it is very small and has 

 little more than negative value. It may reasonably be hoped that the facts 

 set forth in this monograph, and advice based thereon, will serve to prevent 

 other profitless mischances in mining in this area, and make the next work 

 which is undertaken decisive in its results as to the value of these very 

 peculiar coals. 



The first part of this report is limited to the discussion of certain general 

 topics which could not well be treated in the special reports of Messrs. 

 Woodworth 'and Foerste. This has necessarily led to a somewhat incom- 



