ls pass the Etang, though a length of
nine thousand _toises_, with sails. 3. At Agde, by the river Eraut,
twenty-five hundred _toises_. It has but five or six _pieds_ of water
at its mouth. It is joined to the canal at the upper part of this
communication, by a branch of a canal two hundred and seventy _toises_
long. 4. At Narbonne, by a canal they are now opening, which leads from
the great canal near the aqueduct of the river Cesse, twenty-six hundred
_toises_, into the Aude. This new canal will have five lock-basins,
of about twelve _pieds_ fall each. Then you are to cross the Aude very
obliquely, and descend a branch of it six thousand _toises_, through
four lock-basins to Narbonne, and from Narbonne down the same branch,
twelve hundred _toises_ into the _Etang de Sigen_, across that Etang
four thousand _toises_, issuing at an inlet, called _Grau de la
Nouvelle_, into the Gulf of Lyons. But only vessels of thirty or forty
tons can enter this inlet. Of these four communications, that of Cette
only leads to a deep sea-port, because the exit is there by a canal, and
not a river. Those by the Rhone, Eraut, and Aude, are blocked up by bars
at the mouths of those rivers. It is remarkable, that all the rivers
running into the Mediterranean are obstructed at their entrance by bars
and shallows, which often change their position. This is the case with
the Nile, Tiber, the Po, the Lez, le Lyoron, the Orbe, the Gly, the
Tech, the Tet, he. Indeed, the formation of these bars seems not
confined to the mouths of the rivers, though it takes place at them more
certainly. Along almost the whole of the coast, from Marseilles towards
the Pyrenees, banks of sand are thrown up parallel with the coast, which
have insulated portions of the sea, that is, formed them into etangs,
ponds, or sounds, through which here and there narrow and shallow inlets
only are preserved by the currents of the rivers. These sounds fill up
in time, with the mud and sand deposited in them by the rivers. Thus the
Etang de Vendres, navigated formerly by vessels of sixty tons, is
now nearly filled up by the mud and sand of the Aude. The Vistre and
Vidourle, which formerly emptied themselves into the Gulf of Lyons, are
now received by the _Etangs de Manjo_ and Aiguesmortes, that is to
say, the part of the Gulf of Lyons, which formerly received, and still
receives those rivers, is now cut off from the sea by a bar of sand,
which has been thrown up in it, and has form