Horseshoe to the modern hoof boot. Historians differ on the origin of the horseshoe. Because iron was a valuable commodity, and any worn out items were generally reforged and reused, it is difficult to locate clear archaeological evidence. Although some credit the Druids, there is no hard evidence to support this claim. In 1897 four bronze horseshoes with what are apparently nail holes were found in an Etruscan tomb dated around 400 B.C. The assertion by some historians that the Romans invented the "mule shoes" sometime after 100 BC is supported by a reference by Catullus who died in 54 BC.
Horseshoe magnet used, rather than a simpler C-shaped magnet, which is also used, because this places the maximum amount of magnetised material into the magnet, for given dimensions around the poles. A particularly large horseshoe magnet is U-shaped with long parallel sides, rather than the classical horseshoe. Electromagnets are also constructed as horseshoes. They may have either one or two coils wound on them. As most coils are wound by machine, the coil formers are straight. They are thus usually placed as two coils, one on each side of a U-shaped horseshoe. A horseshoe magnet can be created by bending a bar