266 BOARD OF AGRICULTURE. 



that lime of a poor quality might be manufactured from certain 

 rocks occurring in tliis silicious range, and one is the more confi- 

 dent in regard to this when it is remembered that the great lime 

 beds of Rockland lie much less than twenty miles west of the 

 islands. North of the point last mentioned we come upon a sin- 

 gular conglomerate belonging perhaps to the Megunticook series. 

 In its lithological characters it is not much unlike the conglom- 

 erate in Roxbury, Mass., and occurs in much the same manner. 

 This rock varies very much as we push farther north, becoming, in 

 North Haven more like an indurated limestone containing occa- 

 sional pebbles of a fine-grained, slaty character. This conglomerate 

 contains considerable lime, which is not without its effect upon the 

 fertility of the soil. While the south of Vinalhaven, underlaid by 

 syenite, is comparatively infertile, the island of North Haven con- 

 tains many excellent farms. The peculiarity of the conglomer- 

 ate and the amount of calcareous matter present in it, forms a 

 subject of much interest when considered in connection with the 

 lime bearing rocks of Thomaston and Rockland. My duty in the 

 hasty examination of these highly interesting islands, was that of 

 a collector. The specimens placed in your hands, Mr. Hitchcock, 

 will give a correct idea, I trust, of the lithological character of the 

 islands. In my opinion the north of Vinalhaven, and the North 

 island itself, are underlaid by rocks of the same age as those in 

 the Taconic basin of Knox county. 



I am, sir, your obedient servant, 



G. L. GOODALE. 

 Portland, Nov. 1, 1862. 



V ■ . . 



II. Description of a Geological Section from Eden to the Canada 



■ Line. 



By a Geological Section, we mean an exhibition of the strati- 

 graphical relations of the rocks to one another over a given line. 

 This line should always cross the strata as nearly at right angles 

 with them as possible. It is just as if one could see the edges of 

 the strata deep down in the earth, where an immense trench had 

 been dug along the line of the section. Such cuts are frequently 

 exhibited to us in the strata of gravel and sand exposed in bluffs 

 by the crowding action of rivers. The geologist reasons out the 

 position of the solid strata beneath the soil by an attentive obser- 

 vation and comparison of the dips where they are exposed above 



