538 D. MILNE HOME ON HIGH-WATER MARKS ON THE 
lake or an arm of the sea; but being now satisfied by a study of the 
Ordnance contour lines, that they slope down eastward, I allow that they — 
have been formed by river action. 
The flat land, in the Kelso district, about 80 feet above the river, and — 
stretching towards the sea coast horizontally, of course suggests either a lake 
or an estuary. If due to lake, there must have been a barrier at Berwick, 
a supposition so unlikely, that the other alternative seems a necessity. The 
cliffs, which mostly face one another on opposite sides of the valley of the 
Tweed, are im some places 4 or 5 miles apart; another feature suggestive of 
an estuary. | 
A point deserving notice, is the question of exact horizontality of the lines 
last referred to. Near the sea at Berwick, the line of bank seems scarcely 
to be higher than 170 feet above the present sea-level; whereas, towards 
Kelso, the line seems to be between 180 and 185 feet. This circumstance, 
however, if on a more minute survey confirmed, is not incompatible with the 
conditions of an elongated estuary. 
IL.— Districts adjoining the Valley of the Tweed. 
1. The whole surface of the country North of the Tweed, is covered with 
drift deposits. No rocks are visible, except on the river banks or channels, 
till the Lammermuir range of hills is reached. 
South of the Tweed, there are, at several places, conspicuous outcrops of 
sandstone and limestone, and one. or two whinstone dykes. 
The drift deposits are as usual, clay, gravel, sand, and boulders. 
The clay occupies generally the lowest position. It is in the lower districts 
only that brickworks occur. There are none so high as 300 feet above the 
sea. The clay is generally tough and stoney, almost always containing 
pebbles, and frequently boulders. From a brickwork at Paxton (160 feet 
above the sea), there was lately extracted a blue whinstone boulder 124 
tons in weight. The boulder was removed to Paxton Policy, where it 
now stands. 
Beds of gravel and sand abound everywhere, up to at least 1000 feet above 
the sea. 
The beds of sand are extensive. Many near Cornhill, and in lower parts of 
the River Tweed, show a depth exceeding 40 feet. At Mount Pleasant farm, 
near Berwick, about a mile south of the Tweed, the tenant bored down 30 feet 
without reaching the bottom of the deposit. 
The following figure represents a section of the rocks, covered by beds of 
stratified sand and gravel, for a distance of 2 miles along the north bank of 
the Tweed, between the Chain Bridge and the mouth of the River Whitadder. 
The bank here reaches to a height of about 90 feet above the river. , 

