Kamis, 08 Desember 2011

Machine Power

Illustrations by Vittorio Zonca (1607) from
'Novo Teatro di Machine et Edificii'

A levar aque con un moto perpetuo
A perpetual water-raising system
"Zonca shows a large copperplate engraving of a huge pipe for raising water. It had a large, sealed inverted U-tube with larger diameter on one side. The figure shows the larger tube (A) on the left emptying water at a higher level than the water intake on the right. This water then powered a horizontal turbine at the bottom, which drives a millwheel for grinding grain. The sealed port at the top was to facilitate the initial filling of the tube with water.

For want of a better name, I call this a "perverted siphon", though it doesn't work as a siphon*. (It's so hard to name devices that don't work.) Didn't folks in the 17th century know that siphons can only lift water over an elevation if the output tube's opening is lower than the input water level? Perhaps not. Roman engineers had successfully used water tubes or pipes to transport water over hills, but the output was always lower than the input water level. These tubes were a last resort for engineers, for the apex of the tube could not be higher than 10 meters above the water level at the input end. It was difficult to seal the tubes so that air would not seep into the top of the tube and eventually form an air pocket that destroyed the continuity of the water and halted water flow. Perhaps some felt that it was only such practical "engineering difficulties" that prevented the use of siphons to actually deliver water to a higher level.

Remember that the role of atmospheric pressure in these devices wasn't understood. So why did the water stay in the inverted U-tube? This was explained by Aristotle's principle that "nature abhors a vacuum", that is, nature will not allow a vacuum in the top of the tube and will do whatever necessary to prevent it. This explained why a suction pump could lift a column of water (but didn't explain why it could only lift water about 33 feet)." [cont]. {see also}

Vite perpetua chiamata d'altri martinello
Schematics of perpetual screw

Molino fatto col moto degli animali
Mill powered by animals

Machina da voltar spiedi per cuocer le vivande
Gears, ratchets and turning mechanisms for a meat rotisserie

Molino teragno d'acqua
Water-mill (for flour or ..?)

Porte per sostenner l'aqua d'alcun fiume per bisogno della navigation et altro
Mitre gates on a navigational river or canal lock

Ruota per alzar l'aqua
Water raising system (dual power)

Cartiera overo pistogio che pesta le strazze per far la carta
A waterwheel stamping mill - for crushing pulp in paper making

Torchio per stampar i disegni con i rami intagliati
Intaglio-plate {illustration} printing press

Torchio per stampar i libri
Book printing press

Vite perpetua che alza grandissmi pesi
Perpetual screw for raising heavy weights

Molini fatti col movimento dell' aque raccolte
Multi-wheel watermill

Tromba o' schizo per alzar aque in grand altezza
Cross-section of machine/pumping system to raise water to a "great height"

Trombe da rota per cavar aqua
Human-powered water pumping system

As the few online references to Vittorio Zonca (1568-1602) attest, little is known about the Italian architect's life beyond the fact that he lived in Padua and wrote an illustrated technical manual on machines.

Zonca's book -- part of the Renaissance/Early Modern genre known as The Theatre of Machines -- wasn't released until four years after his death, and the illustrations seen above are from the 3rd edition, published in 1656.

In 'Novo Teatro di Machine and Edificii', Zonca presents more than forty engravings that illustrate a wide variety of machines, including presses, grinders, locks, pumps, lathes, weight lifting, load bearing and even water-powered silk throwing systems.

The source for many of Zonca’s designs is believed to be a manuscript by the Sienese painter Francesco di Giorgio Martini (1439-1501), which depicts various 15th c. machines.

Zonca's work was nevertheless important and original because it came closest, among contemporaries in the emerging field of technical manuals, to showing how the mechanical systems would function in the real world. Zonca pared down overly elaborate gear/pulley/lever systems (in which friction would hamper machine operation) and he drew the components mostly to scale, as compared to Ramelli for instance. In other words, Zonca's manual was more practical than (merely) theoretical. References in his book infer that working examples of some of Zonca's machines were successfully built during his lifetime.

In the 1620s, a collection of European machine designs by Zonca, Ramelli and Besson was published in China by the Jesuit scholar, Johann Schreck. The illustrations were produced in a Chinese pictorial style and were the first European technological systems seen in the Far East.

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