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.

Publications: 
Press: 
“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