Bed of nails

A bed of nails is an oblong piece of wood, the size of a bed, with nails pointing upwards out of it.^[1] While it appears at first glance that anyone lying on such a "bed" would be injured by the nails, if the nails are numerous enough, the weight is distributed among them so that the pressure exerted by each nail is not enough to puncture the person's skin.^[2]