History of Naval Medicine
<ALIGN="JUSTIFY">

The Development of Preventive Medicine in the Royal Navy

Introduction
In order to appreciate the development of naval preventive medicine from the earliest times to the present day, it is necessary first to take a brief glimpse at the conditions of life at sea, and enquire into some of the factors and influences which have affected the health and well-being of the sailor through the centuries. There have been four fundamental factors which have governed developments in ship construction, which in turn have had profound effects on conditions of life afloat and the sailor's health. These are slavery, gunpowder, the mariner's compass, and steam.

Slavery
It was slave manpower which worked the fighting galleys of ancient times, such as those of Greece and Rome. These were propelled by oars supplemented by sail. The rowers - one man, three or even five to an oar - were housed sometimes below a deck, and often chained and otherwise barbarously treated. Conditions must have been bad, but mercifully the actual time at sea was short. The other type of ship in these early times was the round ship, a heavy cumbersome sailing ship, without oars, and used for trading. These, too, were manned by slave labour and conditions were likely to be severe. Thus was sown the seed of ill-health among the sailors.

Gunpowder
The discovery of gunpowder and the development of ordnance produced a further big change. The light caravels of the fifteenth and sixteenth centuries gave place to the two or three deckers of the seventeenth and eighteenth centuries, and the placing of guns between decks altered not only the whole construction of ships but of life on board. As the only means of ventilation between decks was by hatches, scuttles and gunports, this had a profound effect on health. The increase in complement to man the guns as well as sail the ship caused overcrowding.

The mariner's compass
The introduction of the mariner's compass was the next big factor. This enabled ships to go on long sea voyages, and the latter half of the fifteenth century saw the beginning of those voyages of exploration which culminated in the great discoveries by Vasco da Gama, Magellan, Cartier and Cabot. It was these long voyages, as will be seen later, that gave rise to scurvy - that great scourge of seamen for the next 300 years. The coppering of ships' bottoms, though not begun until 1761, also enabled ships to keep at sea much longer.

Steam
The last great factor which had an influence on health at sea, and this time a beneficial one, was the introduction of steam power in ships in the nineteenth century. It shortened voyages and led to improvements in living conditions, especially in ventilation. There was an immediate fall in the death rate at sea. The use of steam led gradually to the development of the iron ship entirely propelled by this means, but gave rise to certain problems of ventilation, because of the necessity for watertight compartments separated by bulkheads, and also because iron hulls were powerful conductors of heat and cold. Finally, the use of oil fuel abolished the coal-burning ship and greatly improved cleanliness.