ROYAL NAVY: SAILING AND FIGHTING INSTRUCTIONS SIG/A
Over 153 volumes of sailing and fighting instructions including a printed copy of 1673 issued by James Duke of York. There is a copy of 1691 by Admiral Russel issued in 1702. Subsequent sets show the development which took place up to the Seven Year War. From 1756 onwards additions and supplementary instructions became more numerous. The collection also contains several versions of instructions for ships in convoy 1708 to 1815. Also included is signals and instructions issued during the American War, convoy instructions for 1782 and a number of sets from the 1790’s.
ROYAL NAVY: SIGNAL BOOKS SIG/B
This class consists of over 120 printed and manuscript signal books and signal logs. The earliest signal book is a manuscript volume compiled between 1710 and 1711. There are some manuscript examples produced privately by individual officers usually with a thumb index for quick reference, dating from the mid-eighteenth century. During the 1790s the printing of signal books became general practice. There are various examples (which include day and fog signals), night signals, instructions and additional instructions, which were usually issued in sets. Most of the printed books which were issued have additional signals inserted in manuscript. The manuscript signal books are copies kept by officers who were not issued with a printed signal book and preferred their own copy for easy reference; they are therefore usually pocket size. This practice was forbidden because of the danger of the code falling into enemy hands. However, there are a number of these in the collection and they often contain additional information, such as orders of battle and sailing, keys to both the British and French systems of coastal signals, pendant lists, etc. Many are finely executed, and some are illustrated.
SIGNAL BOOKS: FOREIGN SIG/C
Over half the signal books in this category are French; the other nations represented are Spain, the Kingdom of the Two Sicilies, Sweden and Turkey. The Revolutionary War period is represented by three signal books issued for the navy of the Republic in 1799 and 1801. Only one has been issued and gives a key to the flags. In addition, there is a handbook for a coastal semaphore between Bayonne and Flushing; published in 1807, the system was invented by an artillery officer named Depillon and built ca.1803.
SIGNAL BOOKS: PRIVATE AND THEORY SIG/D
Most of the seven volumes in this category are printed and are either annotated or designed for annotation; they are concerned with naval signalling, telegraphic and merchant shipping codes, 1787 to 1822. The earliest volume is by Captain (later Admiral) Phillip Patton (1739-1815); in 1787 he published 'A system of signals combining the method commonly used in the British Navy...with a numerary method'. As far as is known this was never used, since preference was given to the code invented by Lord Howe (q.v.).
MERCHANT SHIPPING: SIGNAL BOOKS SIG/E
This category consists of two East India Company signal books. The first is a printed signal book of 1783 entitle 'A Collection of Signals for the use of the ships in the Service of the United East India Company'; a sheet of coloured flags has been loosely inserted, but the book was not issued. There is also a manuscript volume of signals issued by Captain Alexander Montgomerie (q.v.) to the fleet under his command, St Helena to England, 1794.

Administrative / biographical background
Flags have long been used to identify a ship's owner or nationality, or the commander of a squadron. Prior to the development of radio, visual signals were essential for communication from one ship to another. The use of flag signals by the Royal Navy is documented as early as 1530 and evolved into an unwieldy system later simplified by Admiral Lord Howe and others in the late 1700s.