302 BOARD OF AGRICULTURE. 



Leaving Sysladobsis lake for the cast, we come first to a long 

 narrow lake five miles in length, and from one mile to one-fourth 

 of a mile in width, called Pocumpus. This is given correctly upon 

 the County Map, but is not laid down at all upon the State Map, 

 there being in its place an enormous body of water called Grand 

 lake. Pocumpus has a north-west and south-east course like sev- 

 eral other lakes and coves in the vicinity. Its shores are ragged 

 but not ledgy. From its southern extremity we passed up a re- 

 markably crooked thoroughfare to Wawbawsoos lake. We found 

 a few ledges of mica schist and micaceous quartz rock with vertical 

 strata, and having a north-easterly course, before arriving at the 

 lake. The quartz rock lies to the west of the schist. Wawbaw- 

 soos or " Machias" lake is very shallow. Near the outlet there is 

 on the shore a short ridge resembling a small horseback, though 

 composed of much coarser materials. Several years ago we de- 

 scribed similar ridges upon lakes in Vermont under the name of 

 Lake Ramparts, from their resemblance to the ramparts of fortifi- 

 cations. This one is six feet high and wide, and not less than a 

 quarter of a mile in length. Something similar was noticed at the 

 foot of Junior lake. They are analogous to the sea walls frequently 

 noticed upon the sea shore of Maine, and specially described in our 

 last report. 



We explain the formation of the Lake ramparts in this way. 

 They are formed by the ice of winter, and only in shallow ponds, 

 or where the water is shallow near the shore, and the bottom is 

 covered with boulders. The ice of the winter seems to inclose the 

 stones with perhaps some of the gravel of the bottom, and from its 

 well known property of expansion it would by freezing gradually 

 force the rocky fragments towards the shore. Li one year the pro- 

 gress would be small ; but in each succeeding winter the work 

 would be resumed, until at length the fragments would be driven 

 to the shore ; and as the level of the lake is commonly higher in 

 the winter than in the summer, they might bo crowded a consider- 

 able distance beyond low water mark, and in the course of ages 

 the accumulation might be very large. Thus the manner of their 

 formation is like that suggested for the formation of the sea walls, 

 except that ice is substituted for water. Farmers who build fences 

 on the edge of a wide ditch often find them prostrated or bent over 

 in the spring, probably for the same reason, that the expansion of 

 the water in freezing has pushed them over. 



