§4.41.1ἐστι δῆλον τὸ γινόμενον.
What is happening is clear.
τοῦ γὰρ Ἴστρου πλείοσι στόμασιν ἀπὸ τῆς Εὐρώπης εἰς τὸν Πόντον εἰσβάλλοντος, συμβαίνει πρὸς τοῦτον σχεδὸν ἐπὶ χίλια στάδια συνεστάναι ταινίαν ἡμέρας δρόμον ἀπέχουσαν τῆς γῆς [ἥτις νῦν συνέστηκεν] ἐκ τῆς τοῖς στόμασιν εἰσφερομένης ἰλύος·
For since the Ister empties into the Pontus from Europe by several mouths, it happens that opposite to this, at a distance of a day's sail from the land, a sandbank has been formed, stretching for nearly a thousand stades, [which is now formed] from the mud carried down by its mouths.
§4.41.2ἐφʼ ἣν ἔτι πελάγιοι τρέχοντες οἱ πλέοντες τὸν Πόντον λανθάνουσιν ἐποκέλλοντες νυκτὸς ἐπὶ τοὺς τόπους.
Sailing towards this, those who navigate the Pontus, while they still think they are running in the open sea, run aground on these places unawares by night.
καλοῦσι δʼ αὐτοὺς οἱ ναυτικοὶ Στήθη.
The sailors call them "Stethe" (Breasts).
§4.41.3τοῦ δὲ μὴ παρʼ αὐτὴν συνίστασθαι τὴν γῆν, ἀλλʼ ἐπὶ τὸ πολὺ προωθεῖσθαι τὸν χοῦν, ταύτην νομιστέον εἶναι τὴν αἰτίαν.
And that the silt is not deposited close to the land itself, but is pushed far out, must be considered to be due to this cause.
§4.41.4ἐφʼ ὅσον μὲν γὰρ αἱ ῥύσεις τῶν ποταμῶν διὰ τὴν βίαν τῆς φορᾶς ἐπικρατοῦσι καὶ διωθοῦνται τὴν θάλατταν, ἐπὶ τοσοῦτο καὶ τὴν γῆν καὶ πάντα τὰ φερόμενα τοῖς ῥεύμασιν ἀνάγκη προωθεῖσθαι καὶ μὴ λαμβάνειν μονὴν μηδὲ στάσιν ἁπλῶς·
For as long as the currents of the rivers, by the violence of their flow, prevail over and push back the sea, for so long must both the silt and everything carried by the currents be pushed forward and find no rest or stoppage at all.
§4.41.5ὅταν δὲ διὰ τὸ βάθος ἤδη καὶ πλῆθος τῆς θαλάττης ἐκλύηται τὰ ῥεύματα, τότʼ εἰκὸς ἤδη κατὰ φύσιν φερόμενον κάτω μονὴν καὶ στάσιν λαμβάνειν τὸν χοῦν.
But when, owing to the depth and vastness of the sea, the currents at length lose their force, then it is natural that the silt, being carried downwards in accordance with its nature, should find rest and a stoppage.
§4.41.6διʼ ἃ δὴ τῶν μὲν λάβρων καὶ μεγάλων ποταμῶν τὰ μὲν χώματα μακρὰν συνίσταται, τὰ δὲ παρὰ τὴν χέρσον ἐστὶν ἀγχιβαθῆ, τῶν δʼ ἐλαττόνων καὶ πρᾴως ῥεόντων παρʼ αὐτὰς τὰς εἰσβολὰς οἱ θῖνες συνίστανται.
For this reason, indeed, the deposits of violent and large rivers are formed far out, and the parts near the mainland are deep close to the shore, while in the case of smaller and gently flowing rivers, the sandbanks are formed close to the very mouths.
§4.41.7μάλιστα δʼ ἔκδηλον γίνεται τοῦτο κατὰ τὰς τῶν ὄμβρων ἐπιφοράς· καὶ γὰρ τὰ τυχόντα τότε τῶν ῥείθρων, ἐπειδὰν ἐπικρατήσωσι τοῦ κύματος κατὰ τὴν εἰσβολήν, προωθοῦσι τὸν χοῦν εἰς θάλατταν ἐπὶ τοσοῦτον ὥστε πρὸς λόγον ἑκάστου γίνεσθαι τὴν ἀπόστασιν τῇ βίᾳ τῶν ἐμπιπτόντων ῥευμάτων.
And this becomes most obvious during heavy downpours of rain; for then even the most ordinary streams, whenever they overcome the waves at their mouths, push the silt out into the sea to such a distance that the interval is in proportion to the violence of each of the incoming currents.
§4.41.8τῷ δὲ μεγέθει τῆς προειρημένης ταινίας καὶ καθόλου τῷ πλήθει τῶν εἰσφερομένων λίθων καὶ ξύλων καὶ γῆς ὑπὸ τῶν ποταμῶν οὐδαμῶς ἀπιστητέον — §4.41.9εὔηθες γάρ — θεωροῦντας ὑπὸ τὴν ὄψιν τὸν τυχόντα χειμάρρουν ἐν βραχεῖ χρόνῳ πολλάκις ἐκχαραδροῦντα μὲν καὶ διακόπτοντα τόπους ἠλιβάτους, φέροντα δὲ πᾶν γένος ὕλης καὶ γῆς καὶ λίθων, ἐπιχώσεις δὲ ποιούμενον τηλικαύτας ὥστʼ ἀλλοιοῦν ἐνίοτε καὶ μηδὲ γινώσκειν ἐν βραχεῖ χρόνῳ
Nor should one in any way disbelieve the size of the aforementioned sandbank, and in general the quantity of stones, timber, and earth brought down by the rivers— for it would be foolish to do so—when we see under our eyes how an ordinary mountain-torrent often, in a short time, hollows out ravines and cuts through precipitous places, carrying away every kind of timber, earth, and stones, and forming deposits so great that sometimes, in a short time, it alters and makes the place unrecognizable.