The Sad Iron: Keeping the Heat in the Face, Not the Hand

Before electricity, clothes were pressed with solid irons — 'sad' meant heavy — heated on the stove and swapped as they cooled. They burned the hand through a hot handle, sent heat up into the ironer's face, and cooled fastest at the point. Mary Florence Potts of Ottumwa, Iowa, patented two answers. US 103,501, dated 24 May 1870, makes the iron a metal shell filled on top and sides with a non-conductor such as plaster of Paris, pointed at both ends, with a wooden handle covering the metal one. US 113,448, dated 4 April 1871, adds a detachable semicircular handle that clips onto any of several hot irons, so the user keeps one cool handle and the wrist stays in line "as a person pushes a plane". This rung models the stored heat and where it leaks, and tests an insulated block against a bare one.