Early Precision Compound Machines

Images: (click to enlarge)
Spiral Ring Machine
Interview: History Channel (Jan 2005)

Distinctive spiral grooves carved on ritual jade rings buried in tombs dating from China’s Spring and Autumn period (771–475 BC) follow a precise mathematical form described by the spiral of Archimedes, 300 years before he lived. I show that the precise drafting would have required a precision compound machine in 550 BC, making it the first machine to precisely interconvert linear and rotational motion by half a millennium, and propose a basic mechanical design relying only upon technologies known to have existed at that time.

“First Compound Machine Found In China,” Popular Mechanics  (Sep 2004)
“Anello cinese rivoluziona la storia della tecnologia,” Corriere Della Sera [Italy]  (Jun 2004)
“Spiral ring reveals ancient complex machines,” New Scientist  (Jun 2004)
“Spirales chinoises,” La Recherche [France]  (Sep 2004)
“Tılsımlı Yüzük,” Atlas Geographic [Turkey]  (Sep 2004)
“Uralte Feinmechanik,” Bild der Wissenschaft [Germany]  (Jun 2004)
“Rotte-dna kaster lys over folkevandring,” Illustreret Videnskab [Denmark]  (2004)
“Ancient Chinese technical tango,” Harvard Gazette  (Jun 2004)

Peter J. Lu  |  Harvard University  |  Cambridge, MA 02138 USA |  plu_at_fas.harvard.edu