Economical Steam Boats. 15 



Should not this and other such testimony silence prejudice, and 

 awaken the attention of a commercial community. The Brindleys 

 built the Rochester Indiaman of four hundred tons measurement, ca- 

 pable of carrying nearly eight hundred tons weight, and many others 

 in the new way, till the navigation interest in general declined in Eng- 

 land, as is well known to have been the fact of late years. Proof 

 was both accidentally and intentionally given of their abundant 

 strength. 



The principle is to place all the materials used in the position that 

 gives strength to the fabric. Accordingly every piece adds to its 

 thickness and tightness. The whole ship is bound together with iron 

 bands like a cask. But instead of being a cask of one thickness of 

 staves, it is composed of a number in succession ; and not only suc- 

 cessively bound on each other, but bolted successively through and 

 through, and drawn together by numerous screw bolts. Then, as 

 every successive coat or thickness of plank is caulked and pitched, 

 the structure is a solid mass of wood and iron and carbonaceous im- 

 pervious imperishable substance. The keel is secured on external- 

 ly, and instead of being a cause of danger from ,its exposed position, 

 serves as a defence ; because it may be even knocked off or ground 

 to pieces by violence without causing the destruction of the hull. 

 Within, there is a kelson and floor timbers to receive the loading. 

 The liability to spring a leak is diminished in proportion to the num- 

 ber of layers. Loading increases the strength of a ship while she 

 floats. 



Insurance and custom not so much influencing construction of steam 

 boats as ships, this method is peculiarly suitable to them ; because 

 they ply principally on our fresh waters and in the heat of summer, 

 when their upper-works are very liable to shrink and admit the weath- 

 er. Of course the causes of decay, heat and moisture operate as 

 powerfully as prematurely. But if the sun can have no effect but on 

 the extei'nal coat, all the others will remain sound. The Messrs. 

 Brindleys observe that their mode of building is very economical, not 

 only because it takes less timber, but requires 7ione that is crooked, 

 which costs twice or thrice as much. Is not this fact worthy of the 

 attention of a naval poiver ?■ Might not the method be fairly tried 

 by government in one instance on a moderate scale ? For it is the 

 premature decay, and necessity of consequent repairs that makes a 

 navy so very expensive even in ordinary. 



