A cased International Code of Signals training set,
by John Morton & Co. Glasgow. Consisting of a partitioned tray of painted metal signal flags, together with a brass mast, slotted to hold a hoist of six flags. 13x12x2.5in (33x30x6cm)
The International Code of Signals was drafted in 1855 and first published in 1857. In consisted of a series of alphabetic and numeral flags, together with three substitutes. Apart from spelling individual words and numbers, combinations of flags could be used with a code book to refer to more complex information. Originally, up to five flags could be used to convey locations throughout the world, however after revision in 1969 a maximum of three code flags are now employed. Thorough knowledge of the meaning of the signal flags and codes was a requirement of Board of Trade examinations for Mariners.