MECHANICS AND USEFUL ARTS. 31 



the bow and the stern. Having then made the width of the ship in accord- 

 ance with the mid-ship section agreed npon, it would be necessary to draw 

 what was known as the wave line on both sides of the bow, and the wave 

 line of the second order on both sides of the stern. Constructed in this 

 manner, and propelled by the ordinary amount of horse-power, the ship 

 would sail precisely ten miles an hour. They could go slower than ten 

 miles an hour if necessary, and in doing so they would economize fuel in 

 consequence of the diminished resistance of the water, whereas there would 

 be a vastly-increased resistance if an attempt were made to di'ive the steamer 

 more than ten miles an hour. Now, with respect to the big ship. For the 

 speed at which it was intended to drive the Great Eastern, it was found that 

 the length of the bow should be three hundred and thirty feet, the length of 

 the stern two hundred and twenty feet, of the middle body one hundred and 

 twenty feet, and of the screw propeller ten feet, making in all six hundred 

 and eighty feet in length. The lines on which she was constructed were 

 neither more nor less than an extended copy of the lines of all ships which he 

 had built since he first laid the wave principle before the Association. It 

 was his pride that he had not put a single experiment or novelty into the 

 structure of the vessel, with one or two exceptions, which he had adopted on 

 the recommendation of men who had had practical experience of their effi- 

 cacy. The wave principle had never, in a single instance, deceived him as 

 to the exact shape a vessel ought to be in order to accomplish a certain rate 

 of speed, and he had therefore adopted it in the construction of the big ship. 

 He would next refer to the mechanical construction of the ship, the arrange, 

 ment of the iron of which she was made, and the objects of those arrange- 

 ments. It was much to be desired that our mechanical sciences should make 

 progress by the simple adoption of what was best, come from where it might; 

 but he was sorry to say that iron ship-building did not grow in that manner. 

 They commenced by servilely imitating the construction of wooden ships, 

 thereby incurring a great deal of unnecessary labor and expense. There 

 was this great difference between the strength of iron and of wood, that, whilst 

 the latter was weak crossways and strong lengthways, or with the grain of 

 the timber, iron was almost equally strong either way. This had been 

 clearly ascertained by experiments made by Mr. Fairbairn and Mr. M. 

 Hodgkinson, at the request of the British Association, in Avhose Transactions 

 the results were published. The consequence was, that the ribs or frames 

 used to strengthen wooden ships, were rendered unnecessary in iron ship- 

 building ; and, acting on this principle, the Wave was built of iron entirely, 

 with bulkheads, and had not a frame in her from one end to the other. He 

 was ashamed to say that he did not always practise what he preached. He 

 Avas compelled, against bis will, by the persons for whom he built, to pursue 

 the old system ; besides which there were laws of trade, acts of Parliament, 

 and Lloyd's rule, to which he was obliged to conform. Thus, if be did not 

 put a certain number of frames on the ship, a black mark would be put upon 

 her, and she would not be allowed to go to sea. But whenever he was al- 

 lowed to build according to his judgment, he built in what he considered to 

 be the best way ; and he believed that in what he was now placing before the 



