Medieval boots were built according to a wide array of architectures. One commonly encountered boot consisted fundamentally of a pair of upright parallel boards that splinted the toes. Turning the screw squeezed the toes between the boards, inflicting lateral pressure on the metatarsal heads and causing agony. Curling the toes over the edge of the boot—typically on pain of being blinded with a dagger—gave the device a stronger grip on the metatarsal heads, thereby enabling the application of maximum pressure and pain. This is the type of boot commonly associated with the torture of Esmeralda in Victor Hugo's "Hunchback of Notre-Dame". Hollywood went out of its way to present exotic, even bizarre, boots that were short on historical accuracy, one of which was little more than dissociated spiked plates lying here and there. The cruelty of the torture could be increased by spacing the toes apart with stiff wooden pegs. Various extensions of the instrument were designed to crush the ankle, calf, or knee in addition to its primary target, the instep. The toes often protruded from the front of the boot, facilitating the infliction of ancillary tortures, such as forcibly tearing the nails from the toes with red-hot pincers or exploring the delicate webbing between the toes with a red-hot iron probe. This type of boot, also called the "brodequin", seems to have been the commonest torture device in France. An alternative "boot" of streamlined design, into which the bare foot was locked with an iron pin, squeezed the toes between iron bars until their bones were fractured. A hinged variant cheaply manufactured from cast iron was used to torture slaves in colonial America. Toe bones were also routinely crushed with mallets, sometimes by cruelly hammering sharp wooden wedges into the tips.