November 4, 2003

Prof. Moon Speaks on History of Machines

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Prof. Francis Moon, Mechanical and Aerospace Engineering, gave a lecture yesterday afternoon in 374 Rockefeller Hall on “The Evolution of Machines from Leonardo to Reuleaux.” A Science and Technology Systems seminar, the lecture focused on how Leonardo DaVinci and others passed on the “language of machines” through visuals.

Moon was introduced by Prof. Bruce Lewenstein, communication, who is also active in the S&TS Department. Moon began by recalling how when he started his time at Cornell, “One professor near retirement had actually used a few” of the old models of machines made by inventors from centuries ago.

Amazingly, in 1967, a group of portfolios by DaVinci were discovered in the Royal Library in Madrid, where they had been lost for almost a century due to a filing mix-up.

Examples of DaVinci’s ideas include the “endless screw,” a model of which is housed in Upson Hall, as well as the “slider crank mechanism,” the “belt mechanism” and the “elliptical mechanism,” which is similar to the exercise machine and to printer belts that move back and forth. A model of this is in the Deutsches Museum in Munich, Germany, which was founded with the aid of a large grant to archive old and original models of machines.

“Was Leonardo DaVinci some kind of a genius, to think up so many inventions?” Moon asked, and explained, “That’s what people thought.” But even more crucial than DaVinci’s intelligence were drawings that passed on knowledge of kinematics and machine design.

Before DaVinci, for example, was Francesco DiGiorgio, who published a book on machine design that DaVinci brought with him from Florence to Milan and probably learned a good deal from. Kinematics from the 1400s through 1800 had a “long tradition of passing on knowledge through visuals.”

“Sometimes you’ll see almost the same picture in books from different centuries, except for the costumes of the people,” Moon continued.

“Was this copying? Plagiarism?” he challenged his audience. No, he asserted. “These were icons of kinematics.” The “language” of machines was learned and passed through the centuries, and on to us.

The study of ancient machines has been hampered by the fact that these pictures are typically not by the actual machine builders; the builders themselves little left behind for us to learn from. In addition, certain models in Berlin were destroyed during World War II. However, the world still has strong collections of models of old machines; there are about 60 models in the Deutsches Museum and 10-20 here at Cornell — an impressive collection.

A new device helpful in the study of machines is the 3-D printer, one of which exists at Cornell. Moon explained how the “printer” “prints” in plastic rather than ink, creating a model of a given machine. He displayed an example of a white plastic model made in this way. Prof. Tarleton Gillespie, S&TS, was especially impressed by the idea of these working models printed out in plastic.

John Saylor, Cornell Information Science, noted that this sort of 3-D “printing process” is “also used in creating ‘E-skeletons’ in universities that use the technique in comparative anatomy to create models of bones of different animals.”

Moon stressed how the mechanics network was passed on because it was visual, and these drawings have greatly enriched our understanding of the progression of kinematics and machine design through the centuries. He finished by describing the power in a well-known name: on a recent trip to Milan, Moon was barred access to seeing original DaVinci works, and was only given permission to see the same facsimiles available to him at Cornell. However, museum officials gave him permission to see “the book that DaVinci probably copied from — the 15th century Francesco DiGiorgio — and they didn’t even ask us to wear gloves!”

Archived article by Lauryn Slotnick