560 Proceedings of the Royal Society 
large bodies of water prevailed over districts which are now dry- 
land. 
As these facts suggest important speculations as to the physical 
conditions and climate of the country, it is desirable that they be 
investigated, before becoming more indistinct from the combined 
effects of weather and land improvements. 
The author divided his paper into the following heads : — 
1. Water lines on the banks of the River Tweed and some 
of its tributaries. 
2. Notice of drift deposits, and appearances of ancient 
lakes. 
3. Theoretical explanations suggested. 
4. Notice of views by other persons. 
I . — Water Lines on Banks of the Tweed. 
(1.) The lowest, and therefore the most recent, water line is indi- 
cated by haugh-lands bounded by a cliff or bank, and at a height 
above the present ordinary summer level of the river of from 14 to 
22 feet, at various places (which were specified) between Berwick 
and Melrose. The line is low where the floods have room to ex- 
pand laterally ; high, where the banks are near one another and 
vertical. To the above-mentioned heights the river rose above 
its present channel on 9th February 1831, being the greatest flood 
which has occurred during the last hundred years. 
(2.) There are two higher water lines, from 22 to 50 feet above 
the present channel of the river. These being older, -they are less 
continuous and less distinctly marked. With regard to them the 
question is, were they reached by the river from its present 
channel, or when its channel was higher? 
(3.) Another extensive flat, more or less horizontal, but appa- 
rently not produced by the river, is at a height of from 115 to 
130 feet above the sea. It is seen on both sides of the Tweed, 
but not beyond Kelso. 
(4.) Traces of two higher flats or terraces exist in the districts 
adjoining the Tweed Valley — one from 170 to 180 feet, the other 
from 200 to 220 feet above the sea. 
