Fig 73.—The Great Republic. American clipper. 1853.
It was not, however, by wooden sailing-ships that the carrying trade of Great Britain was destined to eclipse that of all her rivals. During a portion of the period covered in this chapter, two revolutions—one in the means of propulsion, and the other in the materials of construction of vessels—were slowly making their influence felt. About twelve years before the close of the eighteenth century the first really practical experiment was made on Dalswinton Loch, by Messrs. Miller and Symington, on the utilization of steam as a means of propulsion for vessels. An account of these experiments, and of the subsequent application and development of the invention, are given in the "Handbook on Marine Engines and Boilers," and need not, therefore, be here referred to at greater length.
The other great revolution was the introduction of iron instead of wood as the material for constructing ships. The history of that achievement forms part of the subject-matter of Part II. During the first half of the nineteenth century, good English oak had been becoming scarcer and more expensive. Shortly after the Restoration the price paid for native-grown oak was about £2 15s. a load, this being double its value in the reign of James I. The great consumption at the end of the eighteenth and the beginning of the last century had so diminished the supply, that in 1815, the year in which the great Napoleonic wars terminated, the price had risen to £7 7s. a load, which was, probably, the highest figure ever reached. In 1833 it sank to £6, and then continued to rise till, in 1850, it had reached £6 18s. per load. In consequence of the scarcity of English oak many foreign timbers, such as Dantzic and Italian oak, Italian larch, fir, pitch pine, teak, and African timbers were tried with varying success. In America timber was abundant and cheap, and this was one of the causes which led to the extraordinary development of American shipping in the first half of the nineteenth century, and it is probable that, but for the introduction of iron, which was produced abundantly and cheaply in this country, the carrying trade of the world would have passed definitely into the hands of the people of the United States.
The use of iron and steel as the materials for construction have enabled sailing ships to be built in modern times of dimensions which could not have been thought of in the olden days. These large vessels are chiefly employed in carrying wheat and nitrate of soda from the west coast of South America. Their structural arrangements do not differ greatly from those of iron and steel steamers which are described in Part II.