674 HISTORY AND METHODS OF THE FISHERIES. 
inches. The fluctuations of the same month from year to year are illustrated as an extreme case 
by the record of October, which shows a fall of 1.14 inches in 1874 and 9.57 inches in 1869. As 
compared with other regions, it appears that Maine has a rainfall a little in excess of that of the 
other Northern and Middle States, less than that of Oregon and the Gulf States, and greatly 
exceeding that of England, France, or Germany. The evaporation has been estimated at 60 to 65 
per cent. of the rainfall, and the remaining 35 or 40 per cent. is discharged through the rivers. 
The area of woodland in Maine has probably changed but little since 1869, when Mr. Wells 
estimated it at 21,200 square miles, or 67 per cent. of the entire surface of the State, of which 
61 per cent., is primeval forest.* The latter lies in two principal bodies, which are also contiguous, 
the first by far the greater, occupying the northwestern part of the State, and comprising the 
northern portions of Oxford, Franklin, Somerset, Piscataquis, Penobscot, and part of Aroostook 
Counties; the second in the southern part of the State, in Hancock and Washington Counties, and 
extending at several points quite to the sea. The head waters of all the large rivers and many of 
the small ones are in the wooded districts. These forests consist largely of coniferous trees, spruce, 
hemlock, pine, and arborvite. They contribute in several ways to a constancy in the flow of the 
rivers. The ground is carpeted with moss and leaves, which check the surface flow of water dur- 
ing and after rains, and in the spring the trees shield the vast masses of snow covering the ground 
from the sun and winds, and cause it to melt gradually. The woodland streams are also free from 
the mud and other pollutions that are washed in from cultivated fields and drains of cities and 
villages. Amid these forests, moreover, lie the natural breeding-grounds of the salmon, which are 
doubtless safer there from pursuit than they would be in populous districts. 
The extreme head waters of the largest rivers, the Androscoggin, Kennebec, Penobscot, and 
Saint John, are within 75 miles of each other along the western border of the State in the high- 
lands forming the water-shed between the Gulf of Maine and the Saint Lawrence River. From 
this elevated region, of which the valleys are from 1,500 to 2,000 feet above the sea, and the 
mountain peaks from 1,000 to 2,000 feet higher, streams radiate in all directions, those of Maine 
flowing towards the northeast, east, southeast, and south. 
A secondary water-divide stretches across the State from west to east in latitude 46° 10’ and 
separating the Penobscot from the Saint John basin. This is not coincident with the Appalachian 
hills, which lie mostly to the south. The elevations of this divide are from 1,500 feet in the west 
to about 500 feet in the east. The surface of the State is thus divided into a northern slope of 
7,500 square miles, and a southern slope 25,000 square miles. The former has a gentle inclination 
to the north and east, and is wholly drained into the Saint John. The latter embraces that 
portion drained by rivers emptying into the Gulf of Maine within the limits of the State, and has 
in the western portion a southeasterly and in the eastern portion a southerly inclination, with 
many local irregularities. The southern slope is for the most part accessible naturally to the 
anadromous fishes, but the greater part of the northern slope, about 5,000 square miles, is cut off 
from the sea by the intervention of the impassable Grand Falls of the Saint John River, in 
New Brunswick. 
2. CHARACTERISTIOS OF MAINE RIVERS. 
DECLIviITY.—The rivers of Maine are characterized in the first place by a considerable yet 
moderate descent. The surface of the main slope rises very gradually from the sea to the head- 
waters, and the river beds are sunk very little beneath the general plane. A fall of 1,085 feet in 
140 miles, or 7.8 feet per mile, may ba, taken as representing the mean declivity.t Some of the 
* Wells, Water-power of Maine, page 24, t Wells, Water-power of Maine. 
