S1, E6: Designed by Francesco di Giorgio in the 15th Century during the Renaissance, this saw is meant to harness the power of swift flowing streams and rivers and use this power to cut wood. But does it work and is it more efficient than the two-man pitsaw of its day? The Re-Inventors build their most ambitious prototype to date and then hold their own competition. Its machine vs. man to see if this ancient invention still has teeth. Will this machine, designed centuries before the first sawmill, make the cut, or will they turn it into sawdust?