352 BOARD OF AGRICULTURE. 



We were enabled to confirm the truth of till our observations 

 made last year upon Ileron lake. Especially we found the singu- 

 lar trappean conglomerate, with its immense constituent boulders, 

 one of which is nine feet long. The conglomerate composed of 

 the largest boulders lies adjacent to trap ledges ; and the fur- 

 ther removed from the genuine trap the conglomerate is, the more 

 distinctly the sedimentary character is displayed, and the smaller 

 become the pebbles. On one of the smaller islands these pebbles 

 are arranged in lines of stratification, with the course N. 15° E. 

 We have no longer any doubt that this trappean conglomeiate is 

 truly sedimentary in its origin. Near the dam at the north-west 

 part of Chamberlain lake, are a few ledges of trap. 



No ledges were seen by us between Chamberlain and Chesun- 

 cook lakes. The physical character of the country has been al- 

 ready described. 



In these explorations in northern Maine, we were accompanied 

 by Mr. Oliver White of Richmond, Ind. So much interested did 

 he become in the geology of this part of the State, that at his own 

 expense he undertook the exploration of the route from Chamber- 

 lain to Chesuncook lake, by the way of Alleguash and Cauquom- 

 gomoc lakes, a route never before travelled by any scientific man. 

 His zeal was the more to be commended since the abundance of 

 venomous insects rendered exposure to their attacks almost insuf- 

 ferable, lie wrote out an interesting account of his discoveries, 

 which we herewith present under a deep sense of obligation. 



Alleguash and Cauquomgomoc Lakes. 

 To C. II, Hitchcock, State Geologist: 



Sir : — The subjoined is my report of observations made in ac- 

 cordance with your directions, on the geology of Alleguash and 

 Cauquomgomoc lakes and the vicinity. 



After parting from you at Chamberlain Lake form, June 3d, we 

 rowed directly for the upper end of the lake, and entering upon 

 Alleguash river soon began to discover ledges of the underlying 

 formations. Tlio first ledge seen, two and a half miles up, was a 

 micaceous clay slate, dipping north-west 45°. For nearly three 

 miles these slate ledges are almost continuous, dipping in the 

 same general north-west direction, producing a series of very dif- 

 ficult rapids, and in three places a perpendicular descent of from 

 two to six feet. A few rods above the first falls the strike was 



