1849. 



THE CIVTL ENGINEER AND ARCHITECT'S JOURNAL. 



85 



truly retained, and indeed must remain while the ties are able to 

 keep the abutting surfaces of the parts in close contact. 



The is one point in the remarks contained in your Journal on 

 this subject, which my experience in these structures would seem 

 to indicate as somewhat erroneous; for while aware of the loss of 

 material in rectangular beams generally at the extremities, so far 

 as they depart from the arch, — particularly in cast-iron beams, 

 where the transverse strain acts on the centre, and a depth of 

 material and large sectional area is indispensable. There being no 

 transverse action on these beams, and the centre not being therefore 

 so liable to give way as those parts nearer the abutments, owing to 

 the increased levei'age acting on those parts, I conceive (although 

 admitting the correctness of arching the top chord if practicable) 

 that the height of truss at and near the abutments is requisite to 

 the stability of the beam, and in the case of a very long span, that 

 rigidity would be gained by making the bottom chord in the form 

 of an arch, even if obliged to keep the top chord horizontal; thus 

 decreasing the height of truss at the centre of the span, say one- 

 half, and consequently its own weight, and gradually increasing in 

 weight and proportions towards the extremities, — which is the 

 natural form of a lever supported at one end and left to sustain 

 itself. 



It is evident to my mind, from models and some experiments 

 (although open to conviction), that a structure of the kind de- 

 scribed, suitably proportioned, might be built for a considerable 

 distance from each face of a supporting pier, without the aid of 

 temporary scaffolding ; and I would be willing to undertake to 

 build a bridge involving this principle, on tidal waters or rivers, to 

 swing upon a centre pier as a pivot, and allow a water-way on each 

 side of 70 or 80 feet, the extremities of which should only be sup- 

 ported when brought in line with the two abutments, to accommo- 

 date the passage of trains. 



There is another bridge which may be termed a modification of 

 the foregoing general principle, several of which have been also 

 erected in this country, and are worthy of notice. My remarks 

 have, however, alreadj' gone much beyond my intention, — and ask- 

 ing for them a place in the next number of your valuable Journal, 



I am, Sir, 



Yours obediently, 



Perry-square, Limericlc. Richard B. Osborne, CE. 



Feh. Slst, 1849. 



GOVERNMENT SHIP BUILDING. 



When, in his brilliantly-written " Organization du Travail" M. 

 Louis Blanc propounded his scheme for making government the 

 comptroller-general of national industry, he little thought that the 

 Destiny of Empires would shortly thrust into his hands the means 

 of realising his political theories. Suddenly, however, national 

 work-shojis and all their external machinery was created at his 

 command, and one thing alone was wanted for perfect success— a 

 supply of national workers. For the inhabitants of his palaces of 

 make-believe industry no more deserved the name than do state 

 pensioners generally. 



There is a propensity common to our nature, which, though not 

 formally stated in ethical works, is universal among mankind ; 

 that we all work best hi/ the piece. When a man's industry is 

 rewarded in direct proportion to its results, and not according to a 

 fixed rate, pre-arranged as a probable equivalent for his labours, 

 his exertions receive a stimulus which the most exalted sense of 

 duty and honour cannot afford. Had M. Louis Blanc's pensioners 

 been what he supposed them to be, all brothers, even then his 

 splendid scheme of universal fraternity could have been only 

 partially realised. The will to work for the general maintenance 

 might have existed, but the requisite power and energy would still 

 have been lacking. Poor human nature requires constant encou- 

 ragement and stimulus to animate its exertion; and this is true 

 of all men — prince, philosopher, and peasant, — that no man ever 

 worked long and vorhed hard for the .sake of an abstract idea. 



This is the fatal and irremediable error of all government 

 manufactories; and in England, the public dockyards are the 

 most gigantic exhibitions of its results. From the first Lords of 

 the Admiralty to the meanest ship-carpenter, not one of the whole 

 corps of national ship-builders has a direct interest in producing 

 the best possible ship at the cheapest possible rate. The conse- 

 quences are worse — no, not worse, but just as bad as might be ex- 

 pected. Of all maritime nations, England possesses the worst 

 ships, produced at the dearest rate. The excuse for this result is, 



that the excessive difficulty of ascertaining the proper form and 

 dimensions of a ship, and of predicting its sailing qualities, are so 

 great, that occasional errors in the calculation are unavoidable. 

 We wish to show that this position is untenable, — that the errors 

 do not arise from the complexity of the problem, but from the 

 manner in which it is worked out. Our purpose is to demonstrate 

 that the error is not confined to ship-building, but unavoidably 

 attaches to all government manufacturing. We believe, for exam- 

 ple, that if pins were a government monopoly, their market price 

 would be a shilling a dozen : nor have we the least doubt that if 

 under such circumstances a parliamentary enquiry were instituted, 

 the result would be a respectable blue-book dennuisti'ating by irre- 

 fragible reasoning and the highest official testimony that it would 

 be as impossible to alter the laws of nature as to produce pins at a 

 cheaper rate. 



The sailing qualities of a ship are of two distinct kinds — those 

 relating to her motion, and those relating to her stability. Tlie 

 former constitute a difficult mechanical problem, the latter a very 

 simple and easy one. The former refer to the unknown resistance 

 of fluids, the force of wind, the hydro-dynamical question of the 

 pressure of waves, and the results of the combined effect of these 

 on a curvilinear body. But the latter is simply a hydrostatic 

 problem, which may be solved with perfect certainty and readiness. 

 Were science no more advanced tlian it was in the days of Archi- 

 medes, we might still predict with absolute precision whether a 

 vessel of given dimensions were capable of sustaining the weight of 

 her guns witliout suffering too great an immersion. And in like 

 manner the transverse and longitudinal section of the ship, and 

 the weight of its several parts, would supply sufficient data for 

 ascertaining whether she possessed sufficient stability to prevent 

 her from rolling and pitching excessively. 



Now it is in the easier jiroblem that our government ship- 

 builders so eminently fail. The liistory of a new vessel is com- 

 monly this. First her guns are found too heavy for her weak 

 powers, or if she be a steamer, she reels and groans beneath the 

 burden of her too ponderous engines : this evil partially remedied, 

 either by diminishing her load or enlarging her dimensions, she is 

 at last, perhaps, fortunate enough to reach her destined element, 

 the open sea. But the trials which began at her birth, and unceas- 

 ingly attended her cradle, pursue her in the career of adult exist- 

 ence, — lier calamities are now severer than ever. She behaveth 

 not with the steadiness and dignity befitting her character, and 

 the ponderous respectability of the lords and gentlemen who called 

 lier into being. On the contrary, she rollicks and reels like any 

 harridan : she, the scion of aristocracy, disgraces her noble origin ! 

 and some vulgar craft, built by plain Mr. Jones, passes her in all 

 the dignity and ease of superior virtue. 



To correct the faults of her light behaviour, she is again returned 

 to dock, becomes the subject of much official correspondence, then 

 is cut in two, and lightened or razeed, curtailed here, and pieced 

 out there, until her oldest friends can no longer recognise her. 

 She will sail now, perhaps — not so well as one of the old French 

 ships taken in the last war, — but still she keeps above water. 

 There remains nothing but the bill to pay. 



When mishaps like these occur, not once nor twice, but systema- 

 tically, when the slightest knowledge of mechanics convinces us 

 that they might be avoided, with as much certainty and far more 

 ease than errors in the Bank accounts, — when the expense of these 

 renewed failures is estimated not by thousands but by millions, 

 when the whole country is impoverished and almost overwhelmed 

 by its excessive taxation, — when the national defences are im- 

 perilled by the insufficiency of the navy, — when we find our private 

 merchantmen and foreign men-of-war regularly equipped for sea 

 without these disasters, the investigation of their causes begins to 

 possess some interest. 



How are the Lords of the Admiralty, the Surveyors of the Navy, 

 the Port Admirals, et hoc genus omne, selected ? "Doubtless,"' says 

 the intelligent foreigner, " for their familiarity with naval affairs, 

 their long experience of the practical requirements of a ship, their 

 profound research in the science of ship-building." Simple man ! 

 the First Lord of the Admiralty was never out of sight of land in 

 his life; but then he is of the highest respectability in his county, 

 and his family have always been most consistent politicians. Tlie 

 Port Admiral's uncle regularly divides with the Ministers ; the 

 Surveyor of the Navy is neai-ly related to a bishop ; and the com- 

 mander of the experimental squadron was always making such 

 troublesome motions and inquiries in the House, that government 

 sent him to sea in pure self-defence. 



There appear but two ways of remedying this state of things, 

 and both — so are we trammelled and involved in an artificial sys- 

 tem — but partially practicable. If tlie government ceased to 



