70 _ Remarks on the Geology of Maine. 
The facts which we have observed are of a most interesting 
character, and much time and great labor will be required, in 
digesting and setting in order the various observations which we 
have collected. 
My first object was to continue the outline survey of the sea 
coast, from Blue hill to the New Hampshire line. When this 
was completed, I made a sectional line across the middle of the 
state inland, parallel to the sea coast. Then I made a sectional 
survey, from the mouth of the Penobscott to the gulf of the St. 
Lawrence. 
After this, I followed the east branch of the Penobscott and 
the Lebois to their sources, and passed over to the Aroostook 
river, and followed it down to its confluence with the St. John’s. 
I also surveyed the greater portion of the New Hampshire line of 
Maine. By following this order, the most perfect outlines of the 
geological structure of the country have been obtained, and the 
facts are very important in relation to both science and the arts. 
I have had also to perform in many of my sections, the duties of 
and topographical engineer, since the country was 
almost wholly unknown, and was erroneously laid down on the 
state maps. Difficult and laborious has been the task; but I 
have every reason to feel satisfied, that the work was as carefully 
executed as the time and means in my hands would allow. 
I took great pains to ascertain accurately the altitude of every 
important point by barometrical levelling, and the precautions 
taken ensured accuracy in the results. Having procured two of 
the best English barometers that could be obtained, I took great 
care to bring them to the exact standard, and regulated the ther- 
mometers by a perfect standard French instrument, made ex- 
pressly for me by Collardeau. I then established a line of ba- 
rometrical correspondence across the state; this was done by ma- 
king an agreement with a number of gentlemen to keep exact 
registers of their instruments, the difference between theirs and 
mine having been carefully noted. Daniel Sewall, Esq. of Ken- 
nebunk, Rev. Solomon Adams, of Portland, Prof. Cleaveland, of 
Brunswick, Mr. R. H. Cerdtaee of tiendiner, and O. Frost, Esq. 
of Bangor, were engaged to keep the required registers, and were 
very attentive and exact in their observations. Now the object 
in this plan sets peleesiand, was to be perfectly sure 
that there was no local d yheric pressure, OF 
