Ita cum rota progrediens secum agat tympanum imum et denticulum eius singulis versationibus tympani superioris denticulos inpulsu cogat praeterire, efficiet, <ut,> cum cccc imum versatum fuerit, superius tympanum semel circumagatur et denticulus, qui est ad latus eius fixus, unum denticulum tympani plani producat.
Thus when the wheel moves forwards and carries with it the lowest drum, in a single revolution, the wheel causes its one tooth to strike in passing the teeth in the upper drum. The effect will be that when the lower drum has revolved 400 times, the upper drum will revolve once; and the tooth fixed on the side of the upper drum moves one tooth of the horizontal drum.
final_alignments\Vitruvius_Architecture_Book_10.json