Tom blok Photo collection by Th.Schiöler Water-lifting by draught animals Early Roman sâqiyas Photo 112
Antikke Øseværk
Gul streg
Photo 511 x 506 pixels, 43,6 K
 
The reconstructed right angle gear
From a quarter of the big wheel rim, we can calculate that there must have been in total 48 cogs. In a Greek papyrus from 440 A.D., there is mention of one with 36 cogs.
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