chapter  1
Engineering materials
Pages 12

I found this old nail ( Figure 1.1 ) – some 135 mm long – whilst poking about among the debris from restoration work in the medieval hill-top village of San Gimignano, Tuscany. In the Middle Ages, such nails were made by hand, a blacksmith using a hammer and an anvil, in this case containing a suitable slot so that he could form the nail head. His only additional equipment would be a charcoal fi re assisted by goat-skin bellows to enable him to heat the piece of iron from which he forged and pointed the nail. Because of the way in which they were made, medieval nails were roughly square in cross-section and differed little from those with which Christ was crucifi ed more than a thousand years earlier.