BANKS OF THE TWEED AND SOME OF ITS TRIBUTARIES. 529 
formed by them would not have been horizontal, especially on so great a dis- 
tance as 7 miles. 
These banks suggest rather the presence of a large body of water, which 
covered the plain, and into which streams flowed from the adjoining 
hills. 
There are several circumstances which confirm this inference as to the pre- 
valence of a large body of water, over the plain. 
Thus, towards the central parts, there is a great depth of fine clay, and 
beds of gravel, which are generally above the clay. 
On Ewart estate, the proprietor, Sir Horace St Pauvt, informs me that the 
following borings were made by him :— 
On the low haugh land opposite to Humbledon buildings, where the clay 
is at the surface, he bored down 70 feet, and did not get through it. He 
“went through a few thin seams of gravel.” 
At another place, in boring for water, he went first through 25 feet of dry 
gravel and sand; at that point, having reached the level of the River Glen not 
far off, he went through more gravel and sand, heavily charged with water, for 
about 20 feet, a thick bed of clay was then reached. This clay bed was bored 
to a depth of 100 feet when the rods broke. There was nothing in the clay 
but a few thin seams of gravel. 
Sir Horace mentions that below these beds of clay, there is sandstone rock. 
At one place he reached the rock under about 50 feet of sandy clay. But the 
rock was shattered and extremely hard,—owing, as he supposes, to disturb- 
ances by the Cheviot porphyry. 
At Flodden Brickwork, situated on the eoreNewest side of Millfield 
Plain, the clay is mud and sand in combination. It is known to be at 
least 30 feet deep. A bed of river gravel lies over it about 10 or 12 feet in 
thickness. 
Near Humbledon buildings, having heard that shell marl and peat had 
been found, I took an opportunity of examining both deposits. The bed was 
found at the base of a bank at a level of about 180 feet above the sea. 
Many beds of peat occur in different parts of the plain. 
These facts indicate that a large body of water had prevailed over this 
district, in which sediment had been deposited to the depth of more than 100 
feet. 
At the south-east corner of the plain, near Weetwood House, there are 
several heaps of detritus, at the level of the 180 feet line. As it was there that 
the River Till joined the body of water before referred to, these detritus heaps 
would be de/tas of the river. 
On the diagram a small letter C will be observed at a number of places near 
the 200 feet contour line. The letter indicates the position of old camps or 
VOL. XXVII. PART IV. 7A 
