3o6 : The Atlantic 



but when John Laird in 1829 built an iron hull to be operated as an 

 ocean sailing vessel, trouble started. Everybody knew that a sheath- 

 ing of copper was the only thing that could protect a hull from rap- 

 idly acquiring a coating of seaweed and barnacles and this worked 

 very well on a wooden hull, but when Laird put a copper sheathing 

 on an iron hull and set it afloat on salt water he had unconsciously 

 invited the destruction of his vessel through electrolytic corrosion. 

 It took a long time to get around again to the use of metal hulls. In 

 the meantime iron was frequently used as a material for binding and 

 reinforcing wooden hulls and was employed, for example, by Donald 

 McKay in his larger clipper ships including the Great Republic. 



In the mid-century Brunei, as we have seen, was using iron for his 

 large steamers avoiding the use of copper and counting on paint to 

 keep his hulls from being corroded and overgrown with marine life. 

 In the i86o's a composite hull was frequently employed; this used 

 iron for the framework of the vessel and wood for the planking. 

 The wood was then covered with a copper sheathing so that the 

 metals were separated by an insulating layer of wood. Composite con- 

 struction was employed for some of the clipper ships, particularly 

 those built in England, but iron was coming into increasing use both 

 for sailing and steam vessels and its use was speeded up by the discov- 

 ery about 1870 that paints and other compounds which were chemi- 

 cally hostile to the plants and animals growing in sea water could be 

 applied to metal hulls. By 1880 steel was coming into use instead of 

 iron. 



Still, the whole transition from sail to steam and from wood to 

 metal hulls was mixed and gradual. 



For example, the Great Eastern, launched in 1858, was Brunei's 

 double-hulled iron vessel. In 1859 the British admiralty launched a 

 great warship of 6,000 tons built of wood. In 1868 a steamer called the 

 Japan was launched which was 385 feet in length and was the largest 

 wooden steamship. 



At the same time that these great steamers were being built of 

 wood some of the last of the great clipper ships were being built with 

 composite or with metal hulls. These included vessels like the British 

 clippers Ariel, Taeping and Cutty Sar\. How confused the technology 

 of those days was is well illustrated by the fact that in 1882 the art of 

 freezing meat and of handling it in refrigerators was undergoing 

 rapid development, but the first vessel to carry this kind of cargo 

 from New Zealand to Great Britain was a sailing ship, the Mataura. 

 In that same year as many as 550 sailing vessels cleared the ports of 



