George Fleming, Horse shoes and horse shoeing: their origin… (1869)
“ Such had been the wonderful productions of Coleman and Bracy Clark: frog-pressure shoes, shoes with one or more joints, shoes in segments attached to a leather sole, shoes entirely of leather, shoes without nails to fasten on the foot like a sandal, and shoes in halves, as if for the cloven foot of an ox. In fact, the ingenuity of man appears to have been racked to accommodate this alternate opening and closing of the heels, and the ascent and descent of the sole ”
