Cart weight-load diagram and toothed-rod motions
How front and rear wheels carry the load, with reciprocating gear studies
The lower diagram lays out a cart with letters n, a, c and m: the front wheel at n a partly carries the horse's weight, while the rear wheel bears the load drawn toward c, with the figure 100 noted. Above, two systems of wheels and toothed rods are sketched to produce an alternating motion. The page is drawn upside-down in red chalk.
On this page
Load sharing between a cart's wheels
Leonardo notes that n a partly supports the weight of the horse, that is, the front wheel, while the rear wheel supports the load pulled toward c; the value 100 is entered in the string n a c - 100 - m a n.
Two wheel-and-toothed-rod systems
Two upright mechanisms combine wheels with pegged or toothed rods to convert rotation into a back-and-forth stroke.