SHIPPING: MERCHANT SHIPS OF THE WORLD. In spite of the wealth of literature dealing with the sea and ships, there is very little information about the size of the fleets of the seafaring nations of the world before the nineteenth century. Mulhall estimates the total world tonnage of shipping in 1800 at 4,026,000 tons. This is probably an under-estimate. Sir Henry Petty, writing about 1666, estimated the whole of the shipping of Europe at 2,000,000 tons distributed as follows:— If Petty's figures are reliable, the English must have consider ably improved their position relatively to the Dutch in the first half of the 17th century, for Sir Walter Raleigh writing in 1603/4 states : "We send into the East Kingdoms yearly only one hundred ships, while the Shipowners of the Low Country send thither about three thousand ships." He estimated that the Low Coun tries at that time possessed as many vessels of all sorts as eleven kingdoms of Christendom including England and that they built one thousand ships annually. The sailing ships in which the sea borne trade of the world was carried in the middle ages would to-day be considered of very moderate size even in purely coasting trade. Vasco de Gama rounded the Cape of Good Hope in with three vessels, the largest of which is described as of 120 tons and the first voyage round the world was accomplished by Magellan between 1519 and 1522 with five vessels, the largest of which was only 130 tons. Vessels of greater size were, however, built and King Henry VIII.'s "Harry Grace a Dieu"—the Great Harry—is listed at the head of the inventory (given after Henry VIII.'s death) as of 1,000 tons.
The average size of 152 ships in the Spanish Armada was 389 tons. The English fleet consisted of 76 of the Queen's ships aver aging 121 tons each. The combined tonnage of the Spanish and English fleets was probably less than that of three or four modern transatlantic liners. More or less accurate statistics at any rate for the United Kingdom, the British colonies and the United States of America become available at the end of the 18th cen tury, or roughly from the time of the appearance of the steam vessel. The first patent for a steam engine appears to have been
taken out in 1786 and a small steamer was constructed and em ployed in towing on the Forth and Clyde canal in 1803.
According to a Custom House return of 183o there were 11 steam vessels of 542 net tons belonging to the United Kingdom in 1814. Of these only one steamer of 69 net tons was registered. The 10 unregistered vessels were presumably river craft so that so far as sea-going shipping is concerned the year 1814 may be taken as the official beginning of the steamship era in British mer chant shipping. In the United States records one steam vessel of 78 tons is shown for the year 1807 and 14 steam vessels of 2,917 tons for the year 1814. An accurate statistical account of the de velopment of merchant shipping in the United Kingdom and in foreign countries since 1814 is rendered difficult by the fact that some of the relevant figures are given in net tons and some in gross. The official statistics of the United Kingdom are expressed in net tons throughout, with alternative equivalents in gross tons for later years, but when comparative figures are required for foreign countries reliance has to be placed on the records pub lished by Lloyd's Register of Shipping, and these have in recent years been expressed in gross tons only. In the following tables gross tonnage has been converted into net. The conversion ratios vary with the period of build of the ship, and the "appropriate ratios have been estimated from the data available.
The table on p. 549 shows the tonnage of the merchant shipping on the register of the United Kingdom from 1791 to 1927, so far as the records are available for the earlier years, in some detail for the period 186o to 1890 when the rate of replacement of sail ing vessels by steam vessels was particularly rapid, and yearly from 1914 to 1927.