q TRANSACTIONS OF THE SECTIONS. 197 
calculation to show that while he doubled the money-earning power of a ship by 
increasing its size, he only increased its midship section by 50 per cent. For instance, 
a ship of 2500 tons burden would have 500 feet of excavation through the water to 
do; the big ship had 2000 feet of excavation; and the lineal dimensions of one 
were to the lineal dimensions of the other as 1 to 2°1. The excavation to be done 
by the big ship in relation to that to be done by the small ship was as 4 to 1, but 
the carrying power was as 10 to 1. To propel the big ship they had a nominal 
H.P. of 2500, while to propel the smaller vessel there was a nominal H.P. of 500; 
so that the big ship would be worked quite as economically as the small one. 
Referring again to the wave-line, he would suppose that it was given as a problem to 
any one to design a ship on the wave principle. The first thing to be done was to settle 
the speed at which the ship was intended to go. If the speed were fixed at 10 miles 
an hour, a reference to the table of the wave principle would show that, in order to 
effect that object, the length of the ship’s bows ought to be about 60 feet, and that 
of her stern about 40 feet. If a larger vessel were required, say a ship of 130 feet 
long, there would be nothing more to do than to put a middle body of 30 feet in 
length between the bow and the stern. Having then made the width of the ship in 
accordance with the midship section agreed upon, 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 H.P., the ship would sail precisely 10 miles an hour. 
They could go slower than 10 miles an hour if necessary, and in doing so they would 
economise fuel, in consequence of the diminished resistance of the water; whereas 
there would be a vastly increased resistance if an attempt were made to drive the 
steamer more than 10 miles an hour. 
. For the speed at which it was intended to drive the ‘ Great Eastern,’ it was found 
that the length of her bow should be 330 feet, the length of her stern 220 feet, of 
the middle body 120 feet, and of the screw propeller 10 feet; making in all 680 feet 
in length. The lines on which she was constructed were neither more nor less than 
an extended copy of the lines of all the 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 ex- 
ceptions, which he had adopted on the recommendation of men who had had prac- 
tical experience of their efficacy. The wave principle had never in a single instance 
deceived him as to the exact shape a vessel ought to have 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 big ship, the arrange- 
_ ment of the iron of which she was made, and the object of those arrangements. It 
was much to be desired that our mechanical science should make progress by the 
simple adoption of what was best, come from where it might; but he was sorry to 
_ say that iron shipbuilding did not grow in that manner. They commenced by ser- 
vilely imitating the construction of wooden ships, thereby incurring a great deal of 
unnecessary labour 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, E. Hodgkinson, at the request of the British Association, in whose ‘ Transac- 
tions’ the results were published to the world. 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’ (in the construction of which he 
_ was assisted by two Irishmen) 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 he did 
_ hot always practise what he preached. He was compelled against his 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 he did not put a certain number of frames in the ship, a black 
_mark would be put upon her, and she would not be allowed to go to sea. But 
whenever he was allowed 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 
: 
| 
