PHYSICAL PEATU RES 109 



_ Although, however, when viewed from''any particular point, this 

 plain appears very even, its surface is not quite horizontal. From the 

 southwestern portion of the area the plain rises gently, on going north, 

 until an area of maximum elevation is reached, beyond which it slopes 

 gradually down toward the north, or northeast again. This area of 

 maximum elevation is situated beyond the northern boundary of the 

 sheet. This constitutes the watershed of the region, the waters from 

 it being carried off to the south in a mmiber of small rivers, into large 

 lakes, which lie to the south and west, beyond the limits of the map, 

 and thence into the St. Lawrence ; while along the northern slope 

 it is drained by a number of little streams, which unite to form the 

 Madawaska river. 



The heights of all the points in the area whose elevations have been 

 determined — some 120 in nimiber — ^have been recorded on the map. 

 The elevations being chiefly of points along lines of railway are, natur- 

 ally, somewhat lower than they wotild be for adjacent points on the 

 surface of the plain, the railways following, so far as possible, lines of 

 depression. 



The average height of the plain, as a whole, in the area covered 

 by the map, may be taken as about 1,250 feet above sea-level. In the 

 higher tract referred to above and forming the watershed, it is about 

 1,500 feet. So far as known, the highest point in the area is on the 

 Hastings road, about six nules north of Ma3mooth, in the township of 

 Wicklow, which was determined barometrically to be 1,570 feet above 

 sea-level. 



In the southern portion of the map, the plain continues to slope 

 gently to the south, and eventually passes beneath the Palaeozoic strata 

 which here border it. The lowest points in the whole district are along 

 this contact. Stony lake being only 768 feet, and Deer bay 793 feet 

 above sea-level ; while the roadbed of the Central Ontario railway, 

 which, crossing concession xiv of Tudor, is 1,035 feet above sea-level, 

 sinks to 944 at MiUbridge station, and to 828 at Bannockburn station, 

 four miles and a half farther south. 



The average gradient of the southward sloping portion of the plain 

 cannot be certainly determined with the data at present available, the 

 exact height of a sufficient ntunber of points not being known. If, 

 however, a line is taken from the height-of-land which forms the divide 

 between the Muskoka and Madawaska rivers, in the township of Peck 

 (1,500 feet), in a direction S. 19° E. to the surface of the plain at a 

 point two niiles south of Gooderham (1,213 feet), in the township of 

 Glamorgan — a, distance of 46 miles — the gradient will be found to be 

 6.4 feet to the mile. If a longer line is taken, running a little to the 

 west of that just mentioned and parallel to it, from Canoe lake in the 

 township of Peck (1,379 feet), to Deer bay (793 feet), in the township 

 of Harvey, at the extreme southern limit of the map, the total descent 

 will be 586 feet, and the gradient 8.1 feet to the mile. 



These figures probably represent very closely the average southerly 

 gradient, except along the easterly margin of the area, where the plain, 

 as shown above, has a more uniform elevation from north to south. 



The plain, as has been mentioned, presents by no means a perfectly 

 even surface. It has been etched by the agents of erosion, and is thus 



