Johann Dietrich, Basle, 1755; Iron
height of four outer layers 14.5 cm, width 10.5 cm, depth of two outer layers 0.95 cm
of two inner layers 15.9 cm, width 10.5 cm, depth 9.5 cm
sleeves of brass, partially engraved
The invention of the horse shoe magnet should perhaps be credited to the Basle citizen Johann Dietrich, who produced this example. On both sides of the bend and the ends it is furnished with brass sleeves; on the front of one end is the engraved signature, "Johan / Dietrich/ Inv[enit] et Fe[cit] / 1755", and on the reverse SUD; on the front of the other a Basle crosier and on the reverse NORD. The two middle layers, which are about 1 cm longer, project beyond the sleeves, in order to serve as the magnet. Attached is a piece of iron with moveable hooks on which weights can be hung to demonstrate the strength of the magnet and at the same time to measure it. The magnet is suspended on a special cross-beam by a leather strap.