Her ero o of of Alexa xandria ndria and d His s Aut utomata - PowerPoint PPT Presentation

Di Digi gital tal Ex Expe perim rimental ental Archaeology haeology: : Her ero o of of Alexa xandria ndria and d His s Aut utomata omata in n CAD Duncan Keenan-Jones Classics, University of Glasgow Digital Classicist Seminar, Berlin 15 th November 2016

Overview • Introduction – Hero & his automata • Project aims – Hero and his predecessors – Libation mechanism • Methods – Computer-aided design (CAD) – Mathematical simulation • Hydraulic simulation • Conclusion

Woodcroft 1851 (wikimedia commons) Hero of Alexandria • First century AD • Large number of surviving treatises • Περί αὐτοματο π οιητικῆς : (On the making of the) Automata … ἥτις ἁρμόσει π άσῃ διαθέσει π ρὸς τὸ δύνασθαι τὸν π ροαιρούμενον ἑτέρως διατίθεσθαι ….so that whoever chooses to arrange differently will be able to do it (Hero, Automata 1.1, trans. Grillo) Schmidt 1899 (wikimedia commons)

Hero’s mobile automaton ναοὶ ἢ βωμοὶ σύμμετροι αὐτόματοί τε π ροσαγόμενοι καὶ κατά τινας ὡρισμένους ἱστάμενοι τό π ους , καὶ τῶν ἐνόντων αὐτοῖς ζῳδίων ἕκαστον ἰδίᾳ κινεῖται π ρὸς λόγον τὸν κατὰ τὴν π ροκειμένην π ρόθεσιν ἢ μῦθον ἁρμόζοντα , shrines or altars of suitable size, capable of moving forward under their own power and stopping at certain defined locations; and each of the little figures inside them moves by itself in accordance with either the set purpose or the appropriate story (Hero, Automata 1.1, trans. Grillo)

Drive Mechanism

Programmable 6.1 Ἐπειληθείσης γὰρ τῆς σπάρτου περὶ τὴν ἐξελίκτραν ἐπί τι μέρος, περιτεθεῖσα περὶ τὸν Ξ τύλον τὰ ἐναντία ἐπειλείσθω τῇ πρότερον περὶ τὴν ἐξελίκτραν. … πάλιν οὖν καταφερομένη ἡ λεία ἀπειλήσει τὴν πρώτην ἐπείλησιν, καὶ τὸ πλινθίον πορευθήσεται . (2.) εἶτα ἀποστᾶσα ἀπὸ τοῦ τύλου εἰς τὰ ἐναντία ἐπιστρέψει τοὺς τροχούς. καὶ οὕτως ἔσται ἡ ἀποπορεία τοῦ πλινθίου. ἐὰν δὲ βουλώμεθα πορευθὲν τὸ πλινθίον στῆναι … ἐπειλήσαντες τὴν σπάρτον καὶ περιβαλόντες περὶ τὸν τύλον οὐκ εὐθέως τὰ ἐναντία ἐπειλησόμεθα, ἀλλὰ μηρυμάτιον ποιήσαντες καὶ προσκολλήσαντες [ἐπειλήσομεν] ἐπὶ τὴν ἐξελίκτραν καὶ πάλιν τὰ ἐναντία ἐπειλήσαντες ἀποδώσομεν εἰς τὴν λείαν, καὶ ἔσται τὸ προκείμενον . ( 3.) ἐὰν δὲ καὶ πολλάκις βουλώμεθα πορεύεσθαί τε καὶ ἀποπορεύεσθαι τὸ πλινθίον, πλεονάκις καὶ τὰς ἐναλλὰξ ἐπειλήσεις ποιησόμεθα καὶ τὰ διαστήματα ἡλίκα ἂν προαιρώμεθα καὶ τοὺς τῶν δαιμόνων χρόνους ποιήσομεν διὰ τῶν μηρυμάτων ἡλίκους ἂν προαιρώμεθα. 6.1 When the cord has been wound to a certain extent around the cylinder , let it be looped around the knob Ξ and wound around the cylinder in the direction opposite to the preceding one. … So again, the fall of the counterweight will unroll the first winding, and the case will move. (2.) Then, after the cord detaches from the peg, it will turn the wheels in the opposite direction. This is how the case will come back . However, if we want the case, once it has travelled, to stand still… we will wind the cord and put it around the peg without winding it the other way around immediately. Instead, we will form a little bundle , glue it onto the cylinder, wind the cord again contrariwise and attach it to the counterweight, and what has been said before will happen.(3.) If we also want the case to move forward and backward many times, we will make alternate windings more frequently and the intervals between them the size we choose; we will also make the timings of the deities whatever period of time we choose by means of loops of slack. Rossi & Pagano 2011 J. Mech. Design

Libations π υρὴν (knob) ἀγγεῖον (container) σ ωλὴν (pipe) 13 (1) After the sacrifice, milk must spurt from the thyrsus, and wine from the cup. (2) So, this occurs as follows: a pipe is attached under Dionysos ’ feet, with two holes near one another on its surface; from these, small pipes extend up into the inner part of Dionysos, one leading to the thyrsus, the other to the cup. (3) Let ΑΒ be the base of Dionysos, ΓΔ the pipe connected to it, Ε and Ζ the holes in the pipe, and ΖΗ and ΕΘ the small pipes stretching from these: ΖΗ to the thyrsus, ΕΘ to the cup. Let ΚΛΜ be a knob ( π υρὴν ) placed on top of the shrine. Inside this let ΝΞ be a container with a partition ο in the middle. From the container ΝΟ let a pipe ΠΡΣΤ lead to a certain other pipe ΥΦ , fitted tightly ( συνεσμηρισμένον ) to the pipe ΓΔ and attached from below to the surface on which the shrine rests. (trans. Grillo)

Experimental Strand • Aims – Technical competence presupposed of the reader • How much must be “filled in”? – Practical rather than theoretical? • How feasible? • Had Hero built these automata himself? – Libation mechanism • Could it be constructed? • How impressive in practice?

Hero and his predecessors 1.8 ἐν μὲν οὖν τούτῳ τῷ βιβλίῳ π ερὶ τῶν ὑ π αγόντων γράφομεν ἐκθέμενοι διάθεσιν π οικίλην κατά γε ἡμᾶς , 1.8 Therefore, in this book I will write on mobile automata and set forth a complex configuration of my own 5.1 Οἱ μὲν οὖν πρὸ ἡμῶν τὴν ἐπὶ μιᾶς ὁδὸν τῆς τε πορείας καὶ τῆς ἀποπορείας παρέδωκαν ἡμῖν καὶ ταύτην κακοπαθῆ τε καὶ ἐπικίνδυνον· σπάνιον γὰρ ἐπιτυχεῖν κατακολουθοῦντα ταῖς ὑπ’ αὐτῶν ἀναγεγραμμέναις μεθόδοις, ὡς ἔστι φανερὸν τοῖς πεπειραμένοις αὐτῶν . 5.2 ἡμεῖς δὲ ὑ π οδείξομεν , ὡς ἔστι τὴν ἐ π’ εὐθείας π ορείαν καὶ ἀ π ο π ορείαν γίνεσθαι εὐκό π ως τε καὶ ἀκινδύνως . 5.1 So, our ancestors have handed down to us a way of achieving forward and backward motion along a single line, though troublesome and involving danger; for success is rarely achieved by following the methods they have written down, as is clear to those who have tried them. (2.) I will show that forward and backward motion along a straight line can be performed both easily and without danger…. 20.1 … καὶ γὰρ εὐκό π ως καὶ ἀκινδύνως καὶ ξένως π αρὰ τὰ π ρὸ ἡμῶν ἀναγεγραμμένα κατακεχωρίκαμεν , ὡς ἔστι δῆλον τοῖς π ε π ειραμένοις τῶν π ρότερον ἀναγεγραμμένων . 20.1 … for I have recorded methods which are feasible, riskless and innovative compared to those described by our ancestors, as is clear to anyone who has tested the earlier devices. (Hero, On the making of the Automata , translation F. Grillo)

Methods • Quantitative • Reproducible – Documented, available • 3D CAD Model (SolidWorks) – Design – Simulation • Full scale physical model – Performance testing

3D CAD Model (SolidWorks) Tap – 8 different configurations composed ( κλεὶς & ἐπιτονίον , of 29 sub-assemblies kleis & epitonion) – 185 parts • joined by 249 mates • more than 500 sketches made • the housing or plinthion: 512 features (35 seconds to rebuild)

1) close reading of Greek text • in concert with textual strand (13.5) So, to keep the liquids in (13.5) ἵν’ οὖν στέγῃ τὰ ὑγρὰ τὸν πρότερον beforehand, let ϙ͵τ be a key, which, as χρόνον, κλεὶς ἔστω ἡ ϙ͵Τ ἀποκλείουσα, stated, shuts the liquids off by means of ὡς εἴρηται, τὰ ὑγρὰ δι’ ἐπιτονίου τοῦ ͵Α, a stop-cock ͵α ; let a loop of cord be περὶ ὃ ἀγκύλη σπάρτου περιβεβλήσθω put around this, with some slack to it χάλασμα †ἔχουσα καὶ ἀποδεδομένη εἰς and attached to the counterweight, so τὴν λείαν, ὅπως κατὰ τὸν δέοντα καιρὸν that when it has been pulled taut at the ταθεῖσα ἐπιστρέψῃ τὸ ἐπιτόνιον καὶ appropriate time, it will turn the ἐνεχθῇ τὰ ὑγρά . stopcock and the liquids will be conveyed. (Trans. Grillo)