12 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Jan. 



severe pressure of iron competition Mill induce the present race of 

 ship builders to turn their attention to the means whereby greater 

 strength, security and durability may be given to wooden ships; even- 

 tually perhaps its greater strength for a given weight, and its greater 

 elasticity may obtain a preference. 



Prime cost undoubtedly will form a principal element in the ap- 

 proaching competition; at present iron vessels are often built too 

 cheap, or in other words too slight ; the error may be, and I believe 

 has been remedied. Innumerable questions will arise relating to the 

 elasticity, strength and durability of wood, as well as its qualitv ; and 

 also in reference to the destructive action of salt water on iron, the 

 strain on the rivets, &:o. &c., which can only be answered bv experi- 

 ence. 



To a spirited competition between wood and iron I look for the 

 improvement of vessels of both materials. Recently I have met with 

 parties who being engaged simply as owners on the proposed con- 

 struction of a steam boat, in consequence of the difficulty in the choice 

 of wood or iron, have found it necessary to institute an inquiry respect- 

 ing their relative merits in ship building; these parties, but for the 

 difficulty of selection, would have gone on in the good old jog-trot 

 way of supposing, that British ships of the old construction were per- 

 fect specimens of the art, and would have patiently submitted to the 

 present rates of insurance, as founded on the average loss, deduced 

 from defective ships. The spirit of inquiry once roused among owners 

 of sliipping, will I trust lead to results as yet scarcely anticipated. 



It matters little to the country whether wood or iron eventually ob- 

 tains the preference; if British oak is abandoned it will be only super- 

 seded by British iron, and the inhabitants of our land ought to be satis- 

 fied if the latter will uphold the character of the navy as well as the 

 former has done. 



At present I consider the question of relative superiority as un- 

 decided, and though disposed to admit the inferiority of timber vessels 

 of the common construction, yet the advantages of iron may not exceed 

 that due either to the methods of construction adopted in the navy, or 

 in the Gravesend steam boats. The latter method is perhaps best 

 adapted for small, and the former for large vessels. Moreover, we 

 want the evidence likely to be afforded by the wreck of the largest 

 iron steamers, for the formation of an opinion respecting their powers 

 of endurance under the breakers of a rocky shore, or a sand bank. 



In regard to the relative advantages of the two plans of ship build- 

 ing proposed for the merchant service, the method adopted in the 

 navy has received the stamp of experience, and the evidence is con- 

 clusive in its favour. The oOO ton vessel built of planks before alluded 

 to, was driven on shore in a heavy gale under Mount Batten, in Ply- 

 mouth Sound, when loaded with Ordnance stores, in company with 10 

 or 11 other vessels, all of which became total wrecks ; she afforded an 

 almost solitary instance of a vessel saved, when ashore on that point, 

 and she is reported to have rebounded from the rocks for a short time 

 like a cask, until a hole was knocked in her bottom ; after the "ale 

 she was got oft; and was repaired at a moderate expense, and pro- 

 ceeded on her voyage to the East Indies. 



I should also be inclined to the opinion that a greater strength will 

 be obtained with a less quantity of materials, by means of several 

 series of planks than by close timbers and outside planking, but the 

 latter plan seems to afford greater facility for repairs. In conclusion, 

 I would remaik that it is ray object to assert the possibility of the in- 

 troduction of great improvements in the construction of vessels of 

 wood, without any increase, and perhaps at some reduction of cost, 

 and I wish to induce parties engaged in ship building to advert to the 

 fact, that the best portion of their business, the construction of steamers 

 is rapidly passing out of their hands, and that unless sailing vessels 

 are rendered stronger, safer, and perhaps lighter, this portion of their 

 trade may follow, as the establishments for building iron vessels are 

 increased, or at least such a depreciation of prices may occur as will 

 be equally ruinous to them. 



At the same time I must acknowledge that great improvements in 

 regard to strength have been necessary, and have been adopted in 

 many of the larger steamers, in some instances perhaps to the full ex- 



tent here advocated, at least in the engine room; similar principles 

 might be adopted in the fore and after bodies with lighter timbers, 

 and hence a less strain would be thrown on the midship body in pass- 

 ing over heavy seas. It is their general adoption that I would urge, 

 and I cannot but express my conviction that steam ships of the largest 

 class yet made, may be constructed to bear the winter seas of the 

 Atlantic, by a better disposition of the timber employed in their con- 

 struction. 



Y. 



HAS ATLANTIC STEAM NAVIGATION 

 SUCCESSFUL? 



BEEN 



Although practical men are usually ready to acquiesce in those 

 deductions of the philosopher which relate to the establishment of ab- 

 stract principles, they are too apt to resist any attempt to applv those 

 princi^ples to the analysis of the transactions of real life. General 

 truths are usually treated as if they were individual fallacies: and a 

 hypothesis however just, requires to continue inert in order that it mav 

 remain uncensured. All men look upon general rules as being appli- 

 cable to all cases except those in which their own antipathies or pre- 

 dilections happen to be enlisted, and however clear men's judgments 

 maybe upon indifferent topics, they appear incapable of apprehending 

 the force of the plainest argument if establishing a conclusion adverse 

 to their supposed interests. Hence the imperfect success of attempts, 

 to fix the current value of political or commercial measures by the aid 

 of philosophical research. Some powerful vested interest is sure to 

 step in to prove, "by most sufficient reasons," that the subject under 

 inquiry is exempt from ordinary jurisdictions — that its peculiar fea- 

 tures constitute it a case stii generis which the said vested interest is 

 by far the best qualified to illustrate. Truly the public has much to 

 be thankful for, from an intervention so discriminating and disin- 

 terested! 



But the philosophers are sometimes censurable also. There is a 

 philosophical as well as a popular infatuation, the former consisting in 

 unwarrantable generalization, as the latter in irrational speciality. 

 Things alike are yet things different, and although in the generic dis- 

 tribution of a subject it is impossible to take cognizance of minute 

 differences, yet those differences must by no means be disregarded 

 when an individual case is singled out for examination. Philosophers 

 are too apt to pay exclusive regard to leading characteristics — to 

 overlook those limitations and peculiarities which distinguish every- 

 thing in nature from that which it most nearly resembles, and without 

 an attention to which, general rules cannot be rendered strictly appli- 

 cable to the diversified cases which arise in practice. 



The obvious remedy for these evils is for the practical man and the 

 philosopher each to abate somewhat of his characteristic prejudice. 

 Let the practical man trust a little more to reason, and the philosopher 

 a little more to experience, and let the practical man take the proper 

 steps to cure himself of that mono-mania which the intermingling of 

 considerations of private interest with philosophical investigation 

 usually generates. He should adopt the synthetic rather than the 

 analytic method of investigation, and should be more intent upon trac- 

 ing resemblances than upon multiplying distinctions. He should rea- 

 son from principles to examples rather than from examples to princi- 

 ples, and should lather regard principles as the exponent of results 

 than attempt to raise results into an antagonism of principles. The 

 philosopher should carefully examine whether the case he has under- 

 taken to investigate be not an exception to a general law — or whether 

 it may not possess such distinctive qualities as may materially modify 

 the final result. He should ascertain the precise point at which the 

 case under review diverges from other cases the most nearly coinci- 

 dent, and should assure himself that he has overlooked no circumstance 

 capable of influencing his conclusions. It is only by an observance of 

 these rules that either practical or scientific men may hope to obtain 

 results undistorted by prepossession, prejudice or passion, and we 



