the ships, 270 the machine may be preserved upright and without falling, And against the winds it is necessary to have ready the prepared defenses against siege; to prepare small city-takers like some tower-shaped breastplates or boarding-bridges, being of commensurate height and easy to handle, so that, when the ships get near the wall, then by means of ropes or the aforementioned compound pulleys such machines may be raised, making a way for boarding onto the wall. Effective for such a need the aforementioned tube will also appear, being commensurate in size to the yoked-together 271 ships, if it is moved up and down upon those things set upright, as has been shown before, or upon the so-called carchesium, being able on it to make the six movements, just like the so-called cranes; or even upon a bolt-pin placed on top of a styrax, with the styrax making the rotation upwards and the swing by means of a windlass. Thus then Damis of Colophon also placed the sambucas upon styrakes, as Biton the engineer in his Commentaries on Siegecraft. And all the things said have been set out in diagrams. Let a raft be made, having a length slightly greater than the width of the river about to be bridged, and let it be decked with planks fixed with wooden 272 pegs, so that it may not be driven away by the various motions of the river's current and, being torn apart, be broken. And let most of the raft's timbers be secured with ropes tied to them and with wooden nails sparsely driven in; but let the whole length of the raft that is to approach facing the enemy, along with the two sides on either hand, have a wooden, hinged bulwark of twelve feet in height; and it is made by fixing upright standing timbers that have round holes below and are joined by smooth pins on side planks nailed on from the outside, so that the bulwark does not collapse. And let hides or cloths also be hung upon the planks, projecting a little on the outside; and let ladders be placed inside, having their upper sides pinned to the upright timbers, which are also themselves pierced above, and their lower sides tied with ropes to the deck, so that with the ladders standing nearly upright and bracing it, the bulwark 273 may remain upright facing the enemy. Thus then those standing on the ladders will fight readily against the face of the enemy, being higher up, having bulwarks from the outwork for their own protection and safety. But let the bulwark not be raised all joined as one piece, but let it be unconnected in certain parts, so that, if it becomes necessary during the assault, part of it may stand, and part may fall; and if need be for the whole thing to fall, having untied all the opposing and supporting ladders from the bulwark at their lower parts, we drag them under, placing them upon the deck. And we shall secure this raft by holding it from afar with ropes to stakes driven into the earth; and from the bank on our side, by gradually giving slack to its one end, we shall push it off from upstream, with the wedge holding it being released. And so little by little the raft swings across by the downward rush 274 of the water, like a door being opened, being full of the army; and its one end comes over to the bank of the river toward the enemy. And since it was supposed longer than the river's width, it cannot be turned back downstream by the current. And on the inside of the bulwark on the deck there are holes left in certain parts, going through to the ground, through which wooden stakes are carefully driven in and the raft is secretly tied. And the diagram is like this. And when one end of the raft has reached the opposite bank of the river and has been secured to the ground from inside the bulwark, as was said before, then the other end is also released, and again the downward rush of the current sends it sideways and

τὰ πλοῖα, 270 ὀρθὸν καὶ ἀπαράπτωτον διασώζηται τὸ μηχάνημα, Πρὸς δὲ τοὺς ἀνέμους δεῖ καὶ τὰ ἐμπαράσκευα ἐξ ἑτοίμου ἔχειν τὰ πρὸς πολιορκίαν ἀμυντήρια· μικρὰς παρασκευάζειν ἑλεπόλεις ὡς θωράκιά τινα πυργοειδῆ ἢ ἐπιβατήρια κατὰ τὸ ὕψος σύμμετρα καὶ εὐπρόχειρα ὄντα, ἵνα, ὅταν τὰ πλοῖα ἐγγὺς τοῦ τείχους γένωνται, τότε διὰ σχοινίων ἢ τῶν προρρηθέντων πολυσπάστων τὰ τοιαῦτα ἀνίστωνται μηχανήματα τὴν ἐπὶ τὸ τεῖχος ὁδοποιοῦντα ἐπίβασιν. Ἐνεργὴς δὲ πρὸς τὴν τοιαύτην χρείαν καὶ ὁ προρρηθεὶς αὐλὸς φανήσεται σύμμετρος ὢν τῷ μεγέθει πρὸς τὰ ἐπιζευχθέντα 271 πλοῖα, ἐὰν ἐπὶ τῶν ὀρθίως ἐστηριγμένων ἐπανάγηται μετακινούμενος, ὡς προδέδεικται, ἢ ἐπὶ τοῦ λεγομένου καρχησίου δυνάμενος ἐπὶ αὐτοῦ τὰς ἓξ ποιεῖσθαι κινήσεις, καθάπερ καὶ αἱ λεγόμεναι γέρανοι· ἢ καὶ ἐπὶ κατακλεῖδος ἐπάνω στύρακος ἐπικειμένης, τοῦ στύρακος δι' ἐργάτου τὴν περιστροφὴν πρὸς ὕψος καὶ τὸ πετήσωμα ποιουμένου. Οὕτως οὖν καὶ ∆ᾶμις ὁ Κολοφώνιος ἐπὶ στυράκων τὰς σαμβύκας ἐτίθει, ὡς ὁ μηχανικὸς Βίτων ἐν τοῖς αὐτοῦ Πολιορκητικοῖς ὑπομνήμασι. Τὰ δὲ ῥηθέντα ἐσχηματισμένα πάντα ἔκκειται. Γινέσθω σχεδία μῆκος ἔχουσα μικρῷ μεῖζον τοῦ πλάτους τοῦ μέλλοντος γεφυροῦσθαι ποταμοῦ, καὶ καταστρωθήτω σανίσι ξυλο272 πυρίοις ἐμπησσομέναις, ἵνα μὴ κατὰ διαφόρους κινήσεις τοῦ ποταμίου ῥεύματος ἀπελαύνηται καὶ διασπωμένη ῥηγνύηται. Καὶ τὰ μὲν πλείονα τῆς σχεδίας ξύλα σχοινίοις προσδεδεμένοις καὶ ἥλοις ξυλίνοις ἀραιοῖς καταπεπηγόσιν ἀσφαλιζέσθωσαν· τὸ δὲ κατὰ πρόσωπον τῶν πολεμίων ἐπέρχεσθαι μέλλον ὅλον μῆκος τῆς σχεδίας σὺν τοῖς ἐφ' ἑκάτερα δυσὶ πλαγίοις προτείχισμα ἐχέτω ξύλινον γιγγλυμωτὸν ὕψους ποδῶν ˉιˉβ· γίνεται δὲ κατὰ πῆξιν ὀρθίων ἑστώτων ξύλων στρογγύλας τρήσεις κάτωθεν ἐπιδεχομένων καὶ ὑπὸ λείων περονῶν συμβεβλημένων ἐπὶ πλαγίαις σανίσι προσηλωμέναις ἔξωθεν, μὴ συγκαταπίπτῃ καὶ τὸ προτείχισμα. Κρεμάσθωσαν δὲ καὶ δέρματα ἢ ῥάκη ἐπὶ ταῖς σανίσι μικρὸν παρεξέχοντα ἔξωθεν· καὶ κλίμακες ἔνδον ἐπικείσθωσαν τοὺς ἄνωθεν μηροὺς πεπερονημένους πρὸς τοῖς ὀρθίοις ξύλοις ἔχουσαι, τετρημένοις καὶ αὐτοῖς ἄνωθεν οὖσι, τοὺς δὲ κάτωθεν ἐπὶ τοῦ καταστρώματος σχοινίοις προσδεδεμένοις, ἵνα παρορθίων ἀνθεστηκότων τῶν κλιμάκων ὀρθὸν διαμένῃ ἀπαντώμενον τὸ προ273 τείχισμα. Οὕτως οὖν οἱ ἐπὶ τῶν κλιμάκων ἑστῶτες εὐπροθύμως ἀντιμαχήσονται κατὰ πρόσωπον τῶν πολεμίων ὑψηλότεροι ὄντες, προπύργια εἰς φυλακὴν ἑαυτῶν καὶ ἀσφάλειαν ἐκ τοῦ προτειχίσματος ἔχοντες. Μὴ ἑνούσθω δὲ ὅλον ἀνιστάμενον τὸ προτείχισμα, ἀλλὰ πρὸς μέρη τινὰ ἀσύνδετον ἔστω, ἵνα, ἐὰν ἀνάγκη κατὰ τὴν προσβολὴν γένηται, τὸ μὲν αὐτοῦ ἱστᾶται, τὸ δὲ καταπίπτῃ· εἰ δὲ χρεία γένηται καὶ ὅλον καταπεσεῖν, πάσας τὰς ὑπαντώσας κλίμακας καὶ ἀντεχούσας ἐπὶ τῷ προτειχίσματι λύσαντες ἐκ τῶν κάτωθεν μερῶν ὑποσυροῦμεν ἐπὶ τοῦ καταστρώματος ἐπιθέντες. Ταύτην δὲ τὴν σχεδίαν πασσάλοις τῇ γῇ ἐμπεπηγόσι μακρόθεν διὰ σχοινίων ἀποκρατοῦντες ἀσφαλισόμεθα· καὶ ἐκ τοῦ πρὸς ἡμᾶς χείλους τὸ ἓν αὐτῆς ἄκρον κατὰ μικρὸν ἐπιδιδόντες ἀπελάσομεν ἄνωθεν, τοῦ ἀποκρατοῦντος αὐτὴν ἀπολυομένου σφηνός. Καὶ οὕτως κατὰ μικρὸν ἡ σχεδία παρέρχεται ὑπὸ τῆς τοῦ ὕδατος κατα274 φορᾶς καθάπερ θύρα διανοιγομένη, τοῦ στρατεύματος πλήρης οὖσα· καὶ μετέρχεται τὸ ἓν αὐτῆς ἄκρον ἐπὶ τὸ χεῖλος τοῦ ποταμοῦ τὸ πρὸς τοὺς πολεμίους. Καὶ ἐπεὶ μακροτέρα τοῦ ποταμοῦ πλάτους ὑπετέθη, οὐ δύναται ὑπὸ ῥεύματος πρὸς κατάρρουν πάλιν ἀντιστρέφεσθαι. Τοῦ δὲ προτειχίσματος ἔνδοθεν ἐπὶ τῷ καταστρώματί εἰσιν ἀφεθέντα τρυπήματα πρὸς μέρη τινὰ καὶ μέχρι τῆς γῆς διερχόμενα, πρὸς ἃ πάσσαλοι ξύλινοι ἐπιμελῶς πήγνυνται καὶ προσδέδεται κρυφίως ἡ σχεδία. Καὶ ἔστι τὸ σχῆμα τοιοῦτον. Ἐπελθόντος δὲ τοῦ ἑνὸς τῆς σχεδίας ἄκρου ἐπὶ τὸ ἐναντίον χεῖλος τοῦ ποταμοῦ καὶ πρὸς τῇ γῇ ἀσφαλισθέντος ἔνδον τοῦ προτειχίσματος, ὡς προείρηται, τότε ἀπολύεται ἐξ ἄκρου καὶ τὸ ἕτερον, καὶ πάλιν ἡ τοῦ ῥεύματος καταφορὰ πλαγίαν αὐτὴν ἐπιπέμπει καὶ