We put things in order - God does the rest. Lay an iron bar east and west, it is not magnetized. Lay it north and south and it is. Horace Mann
Heat can also be produced by the impact of imperfectly elastic bodies as well as by friction. This is the case, for instance, when we produce fire by striking flint against steel, or when an iron bar is worked for some time by powerful blows of the hammer. Hermann von Helmholtz