APPENDIX, N" II. 
521 
was supposed, that, as only one sand-bank, 
of 150 feet in extent, with seven feet water, 
remained, and obstructed the passage of ships 
drawing six feet, it might be deepened, par- 
ticularly during the winter, by working on the 
ice with certain machines in use at Plymouth 
(dr agues). This work could not, at any rate, 
be executed in less than ten years ; and from 
the constant accumulation of sand, must ever 
be continued, as at the River Charante in France. 
There is a road for ships, five versts from the 
estuary of the Dvina, at Dunamund, with four- 
teen feet water, and fit for ships drawing thirteen 
feet; but its situation will not admit of any 
amelioration, whatever safe, artificial haven or 
port might be constructed on the left shore, 
both for men-of-war and merchant ships; but 
an enterprise so stupendous has hardly ever 
been attempted; and it would require such 
immense sums, that the Board has resolved 
not to enter upon it, nor attempt deepening 
the passage at the Damba. 
The following Rivers fall into the Southern Dvina 
or Duna. 
The Buldera, which joins it at the fortress 
of Dunamund. Vessels navigate this river, 
passing Milan as far as Bansk, near which it 
divides itself into two branches ; the one 
