APPENDIX, N* II. 
The Southern Dvina, or Duna, being the chief 
outlet into the Baltic, after the Neva, from all 
the interior provinces as far south as Kiof, for 
the exportation of their products, forms a sepa- 
rate division of inland navigation. This river is 
navigable to the town of Sourash. About one 
thousand barks, with goods, frequent it annually, 
besides a great number of rafts for timber and 
mast wood. This traffic is likely to continue, 
notwithstanding the great difficulty and ex- 
penses attending the navigation of the river, 
which, from the very town of Drisno, is filled 
with stones, some under water, some projecting 
above it. All possible means were adopted to 
deepen and widen the channel, which, at the 
estuary, is also subject to be choked up, by 
moving bodies of sand. It was supposed, that 
by increasing the natural current or stream of 
the river (or increasing the rapidity), by nar- 
rowing it with dykes or dams, these bars to 
navigation would have been removed ; but the 
execution of this plan proved not only abortive, 
but very pernicious, as it caused an inundation 
which threatened with destruction the low 
country about Riga: this was only saved by 
the undermining or washing away of the dykes, 
and the stream making itself a new channel, or 
outlet, at a hollow road called the Duna-ravin. 
After the stream had taken this new course, it 
