"Machines on Paper," Markus Asper

• From Words to Acts, Introduction
• Machines result from a process of construction.
• Antikythera device: oldest analogue computer for predicting astronomical positions and eclipses.
• Antikythera device is more celebrated than Hero or Aristotle's writings on mechanics or Briton and Philo's treatises on catapult making.
• Athenaeus: two acts of doing mechanics, (1) learning about it and (2) turning it into practical effects
• Athenaeus views the learning about it to be completely irrelevant from practical investigation, and "doing" is much more important.
• Athenaeus, sarcastically: "When this piece of work is well devised, a great reputation of its builder will emerge; but when someone explicated it in words, the description will have most renown in technical writings."
• Mechanics: everything from geometrical proof of the law of lever to details on siege-craft.
• Acts, from most practical to least practical:
1. the practical construction of machines
2. comprehensive and systematic knowledge about the construction of machines
3. decision-making with regard to purchasing machines and paying engineers
4. the proper scientific explanation of how and why machines work (quasi-mathematical proofs)
• Constructing Machines
• Mechanical knowledge solves practical problems (extracting oil from olives, how to lift great weights, constructing siege engines)
• Writing about mechanics can be unclear to the reader, perhaps intentionally, because of the respect of the material or an assumed expert audience.
• Asper focuses on (1) numbers and diagrams, and (2) structure.
• Asper gives Cato's number based description of an olive press:
• 'Trees' two feet thick, nine feet high including tenons, with sockets cut out 3 3/4 feet long and 6 fingers wide beginning 1 1/2 feet from the ground. ...
• Cato's readers apparently knew what he was talking about.
• Asper compares Cato's description with Hero's description 250 years later, where Hero analytically describes the olive press instead:
• The beam called 'mountain' which others call 'press' is nothing but a lever and its fulcrum.
• Both Cato and Hero do not refer to a diagram.
• Olive presses were well-known at the time, but artillery constructions were not. Asper gives Biton's description of Zopyrus' mountain bellybow:
• There is a base, A, the length of which is 5 ft., the breadth 3 1/2 ft., the height 1 ft.
• The description does refer to a diagram (which was lost) but even with the diagram, the information would not be sufficient to understand its construction.
• To understand the information, you would have to go to its inventor Zopyrus or the place where it was constructed. Thus, the description is just a supplement.
• To give exact measurements lends credibility to the author, suggesting the author has direct access to the machine.
• Exact measurements also give credibility that there is a machine that actually works because they could measure it...
• Apprentices would learn the principles by practicing the recipe.
• Asper cites Biton and Philo explaining the importance of proportions (Philo here):
• Therefore, I insist that one must be careful when one adapts the construction of successful machines to own's own construction, especially when one wants to enlarge or diminish the scale.
• Philo explains problems were solved experimentally at first, but then solved mathematically.
• Asper explains the necessity of a diagram by sharing a description from Hero's manual:
• You construct a template like AB DEZ is illustrated, with AE and BZ curved, E and ZD straight, and AB equal to the diameter of the whole.
• Explaining this without the diagram would have been problematic.
• 'Machines on paper' must always work, so the diagrams serve as an illusion, convincing the reader the machine works smoothly.
• Asper compares the language of theoretical mathematics with absurd, Platonizing authorial voices (Biton given second):
• Let there be a such-and-such ABC...
• Let the proposed belly-bow be the one which Zopyrus of Tarentum designed at Miletus.
• Asper concludes this first section by arguing diagrams are necessary to get the machines off paper.
• Codifying Knowledge about Machines
• In addition to knowledge on how to construct a machine, it must also be known how to acquire, store, transmit, and keep the knowledge accessible.
• Examples of mechanical technai: Vitruvius' On Architecture and Hero's Mechanica.
• Main features of Greek theoretical knowledge:
• (a) to define a field of knowledge and several subfields within it
• (b) to identify, name, and define elements of analysis to which all objects of discourse can be reduced
• (c) to arrange these elements in such a way that causal structures become cognizable
• Vitruvius explains a machine exists in a subfield of physics concerned with circular movements:
• A machine is a constant construction from wood that exerts the greatest forces towards moving weights. It moves by the revolutions of circles, which the Greeks call circular movement.
• One reason Vitruvius wrote: to seek patronage from an emperor.
• Hero, at the height of his institution, did not seek patronage. Nonetheless, their basic intentions were comparable.
• Hero's first book tackles the generalization of the problem: moving a given weight by a given force.
• Hero's second book explains five basic machines: windlass, lever, pulley, wedge, and screw.
• Hero's third book is more practical, explaining presses.
• Hero's overall approach creates a systematic map of mechanical knowledge that applies to all subfields of mechanics.
• Hero's approach guarantees his communicative success.
• Deciding about Machines
• Athenaeus includes a story:
• The ones in the siege of Chios, having taken aim wrongly and having constructed sambucas (scaling devices) that were higher than the towers, they caused the ones who went up on them to die from fire because they could not get tot he towers and it was not possible in any way to lower them. Therefore, among other fields, the technician who wants to use machines must not be inexperienced in optics.
• Construction knowledge concerns not just the act of construction but also decisions about how to use them.
• Automata was used to marvel for patronage or court culture. The point of automata was to impress the observer by suggesting the apparatus does something unimaginable: move by itself.
• Hero had a device for a sacrificial fire to open and close doors.
• The rhetorical "mathematization" of their knowledge might be a part of a corresponding strategy to secure a position higher up the social ladder and thus closer to the center of power and knowledge than mechanics used to be.
• Understanding Machines
• Odd, according to Asper: the desire to understand or to explain the principles of devices one uses every day.
• Author's focus: subjecting phenomena to rigorous explanation. (Rigorous like Euclid.)
• "the marvel only fulfills its proper function when spectators discover and understand the craft of the illusionist mechanic, the theoretical treatise which focuses on explanation, unveils the omnipresence of levers in our world which we use all the time without ever thinking about them and without even knowing theoretically the concepts of levers."
• This pursuit shows a fascination with insight. It does not help explain how a machine works. It is simply the pleasure of understanding the world around us, which is part of how machines work.
• Instead of a Conclusion: Further Questions
• The main practice of ancient mechanics was not writing.
• Competition, however, has made writings being able to achieve authorial success.
• Hero gives his personal goal:
• My predecessors have composed a great number of detailed treatises... but it is as if they have written down the details for all the readers who already know.
• He wants to give an account that is "easy for everyone to follow."
• Reading Journal
• Asper explores the construction of machines from four points (1) how to construct machines, (2) how to use machines, (3) why to construct machines, and (4) how machines work. Asper makes an interesting point at each step along the process. In (1), authors use numbers to lend themselves credibility. Since they are giving exact numbers, they must therefore be a direct witness of this successful machine. The numbers further lend credibility that the machine itself works as described, because once again the author is taking the exact measurements of the device that they are claiming works. In (2) Asper cites Hero as giving a systematic approach (explaining a practical problem that is first given from a general problem) that guarantees his communicative success. In (3), Asper explains authors use rhetorical "mathematization" of their knowledge to secure patronage or move up the social ladder. In (4), Asper finds explaining things we use every day as the strangest part as the oddest part of this process. Different from (2) where explaining how it works is necessary for construction, but in (4) authors explain things we take for granted with Euclidean rigor, explaining how machines work by reducing them to basic principles of physics. Overall, the take away is that these ancient technical writings should not be viewed from our user manual perspective. They do more than provide a user manual.