Dal saper come fare al saper cosa fare

“The tools and processes of shoemaking in all countries and ages prior to 1830 were few and easily mastered [..] there have been: 2 parts to a shoe: an upper and a sole; 4 processes in making a shoe: cutting, fitting, lasting, bottoming; 8 tools necessary for making a shoe: Knife, awl, needle, pincers, last, hammer, lapstone, and stirrup. [..] In a modern shoe factory, there are one hundred separate operations performed in making one shoe.” (Blanche Evans Hazard, 1921)