Compass

The dry mariner's compass was invented in Europe around 1300. The dry mariner's compass consists of three elements: A freely pivoting needle on a pin enclosed in a little box with a glass cover and a wind rose, whereby "the wind rose or compass card is attached to a magnetized needle in such a manner that when placed on a pivot in a box fastened in line with the keel of the ship the card would turn as the ship changed direction, indicating always what course the ship was on".

Later, compasses were often fitted into a gimbal mounting to reduce grounding of the needle or card when used on the pitching and rolling deck of a ship. The construction of many early (mid-18th century) binnacles used iron nails, which were later discovered to cause magnetic deviations in compass readings. As the development of the compass and understanding of magnetism progressed, greater attention was given to binnacle construction to avoid compass disturbances caused by iron.