By examining a map o f Ruffia, we find that the Tvertza Cy^F'
joins the Volga at Tver ; that the Shlina forms the lake >— «— <
Maftino, which gives rife to the Mafia : that the latter falls,
after a courfe o f about 234 miles, into the lake Ilmen, from
which iffues the river Volkof, and runs 130 miles to the lake
Ladoga, which fupplies the Neva: fo th a t , in effe<5t, the
Shlina, the Mafia, the Volkof, and the Neva, may be confi-
dered as the fame river, flowing into and through different
lakes, and only changing its name at various intervals. By
uniting, therefore, the Shlina which communicates with the
Baltick, with the Tvertza which flows by the Volga into the
Cafpian, is formed the junction o f thofe two feas. This
jundtion is made by the canal o f Viihnèi-Volofhok, where the
Shlina is united to the Tvertza by the following canals and
rivulets, for the relative fituation o f which I ihall refer to
the figures in the annexed plan.
Clofe to Vifhnèi-Voloihok, the' Shlina is formed by the
confluence o f the two rivulets Shlina and Zna; near the latter
are -the fources o f the Tvertza. In order to join the
Tvertza and the Zna, the following works were made under
Peter the Great.
i . Near the village o f Klutihina a cut was dug to the
fmall lake of the fame name ; a fécond to the lake o f Goro-
dolub ; and a third from thence to the Zna. 2. At the
fame village, juft below the firft cut, a lock o f four gates
Was conftrudled acrofs the Shlina, in order to flop the courfe
of that rivulet ; and, by means o f the faid cuts and lakes, to
çonvey water to the Zna above Viihnèi-Vololhok. 3. But
to keep this fupply o f water in referve, and to let as much in
to the town as is judged neceifary, a great lock o f feven gates
was built acrofs the Zna below the third cut. 4. The Zna
and the Tvertza were united by a canal, beginning from the
p p 2 \ fources