It may be unexpected to some to find that among all the unsolved problems in the history of the magnetic compass there is a shortage of information on the form and arrangement of binnacles during the eighteenth and first part of the nineteenth centuries. The cupboard type of binnacle designed to take one or two steering compasses, according to the size of the ship, is pretty well documented for it is described in most of the books on navigation published in the French and English languages from the middle of the seventeenth century. There are also drawings in some books and there is a watercolour in the National Maritime Museum which shows the steering binnacle on the deck of His Majesty's Ship Deal Castle about 1775. This is however the only deck scene of the period known to me which does show a binnacle and very few binnacles appear in contemporary ship models.