[ELLS] GEOLOGY OF THE OTTAWA PALÆOZOIC BASIN 105 
river is at no point presumably more than fifteen miles, and the general 
course of the depression appears to be fairly straight, From Ottawa, 
the depression can be followed to the Mer Bleue and the vicinity 
of Eastman Springs, the difference in elevation between the Cen- 
tral station in this city and the latter point as taken from the pro- 
file of the Canada Atlantic railway being only twelve feet. At Bear 
Brook the next station east, the elevation of the railway is twenty-two 
feet higher and at Casselman, which is on the Nation river, the eleva- 
tion is only four feet higher than at the station in Ottawa, or 216 feet 
above mean high water at Quebec as already noted. 
East of the Mer Bleue the line of the old channel apparently fol- 
lows the course of a stream known as Bear Brook which joins the Nation 
river at the sharp angle in the west part of the township of Plan- 
tagenet. From this point it follows the east stretch of the Nation to 
the Elbow where it turns north to join the Ottawa, and thence it con- 
tinues east to Caledonia Springs, beyond which its further course has 
not been definitely traced. 
Along the portion west of the Nation river the land rises and forms 
a rocky ridge in the part between the course of this old channel and the 
present course of the Ottawa, while to the south also rocky outcrops are 
seen, and the formations are in many cases but a short distance below 
the surface. The depths of the borings along the line thus indicated 
range from 100 to 150 feet, and in one point a depth of 210 feet to 
the rock was found. This is the deepest boring in the clay yet re- 
corded in this district. 
Along the present channel of the Ottawa some interesting results 
were obtained from this series of borings. Thus near the Montreal 
road not far from the crossing of Green’s creek, the rock was reached at 
a depth of 125 feet. At the village of St. Joseph d’Orleans on the 
same road, about four miles east of the last place, the same depth 
was obtained, while two miles south of this place the thickness of the 
overlying deposits was only thirty to fifty feet. Near the corner of the 
townships of Russell, Cumberland and Osgoode, a depth of 114 feet was 
found, while in the vicinity several other holes were bored which showed 
a depth of drift of from sixty to seventy-five feet. 
At Cumberland village on the Ottawa, the clay was pierced at a 
depth of eighty feet. At Sarsfield about ten miles south of this place, 
near the summit of the ridge, the rock was reached at a depth of only 
twenty-five to thirty feet, while at other points near by the thickness 
of the drift was only ten feet. 
At Bear Brook, on the Canada Atlantic railway, several holes 
were bored to depths of seventy-five to 100 feet, and the same thick- 
