438 
HULLETIN OF THE NATURAL HISTORY SOCIETY. 
most of the troublesome rapids on our rivers, notably on the St. Croix, 
the Nepisiguit, and the Southwest Miramichi. Small falls of this 
type occur also commonly at the outlets of lakes, and at the lower 
-ends of long dead-waters. 
3. Affluent Falls. — In the process of erosion of any country, 
the larger, especially if sediment-carrying, rivers tend to wear down 
their channels more rapidly than do the smaller branches, especially if 
these be clear streams. This process may often have been aided by 
glacial erosion of the greater streams.* Hence, the smaller branches 
must enter the larger valley with a fall, which will not be a vertical 
drop, but an irregular sloping fall or rocky rapid. Very large branches 
would not show such a fall, since they would cut down as rapidly as 
the main stream.. If now^ we note the way in which the smaller 
branches of our principal rivers enter the main valleys, w^e will find 
that it is usually with either a broken fall or else with rocky rapids. 
This is true, for instance, of most of the streams entering the St. John 
between Grand Falls and the head of tide above Fredericton. The 
phenomenon is less marked than it would otherwise be since the main 
river is, for the most part, not flowing in its ancient rock bed, but 
upon drift with which it is partially filled. Some of the falls at the 
mouths of these branches may be of glacial origin ; indeed, they may 
all be, for the subject has not received, though it deserves, investi- 
gation from this point of view. 
4. Plateau Falls. — New Brunswick is largely of the physio- 
graphic character known as rejuvenated, that is, consists of great 
imperfect peneplains which have been re-elevated, thus allowing the 
rivers to cut their valleys deeply into them. On the resulting plateaus 
new streams are of course forming ; and where these reach the valleys 
of the older rivers, they make a long fall into them, which may be 
steep even to vertical. Thus is produced, I believe, the highest fall 
in the province, namely, that on Fall Brook, on the southwest Mira- 
michi, a few miles above Boiestown. This fall, 120 feet in height, 
and a single vertical drop into a beautiful rocky basin, occurs just 
where the brook meets the valley of the main Miramichi. The next 
highest. Hays, or Thompson’s Fall, below Woodstock, is also of this 
character, as are the falls on the brook emptying Milna'gek or Island 
* Davis (Science, xiv, 779) appears to advocate the view that where such “hanging: 
•valleys ’’ occur, the main stream has been deepened by glacial ice. 
