Tae discussions now going on in England with regard to the strength of ships and their seaworthiness, cannot fail to have in the long run a beneficial effect. Cases like those of the Mary and the Chusan have drawn attention to the diversities of opinion existing between the builders and the classifiers, amd much the same question arises on the mootpoint of the compulsory marking ofa load-line. Recent changes both in storage and in the course of trade have necessitated the construction of ships of very different dimensions from what we wore accustomed to, even so lately as fifteen or twenty years ago. It has been calculated that the tension on the upper works of a ship of 3,000 tons is one and-a-half times as great as om a 1,500 ton ship, twice as great as on a 700 ton ship, and five times as great as on a 100 ton vessel. The tendency now-a-days is to construct vessels Approaching nearer the former' than the Intter limit, and as a consequence the question of strains becomes daily of move importance. Hydraulic packing Ins almost done away with the old style of measurentent cargo, and a dead instead of an elastic weight has now generally to be taken into considera tion, Tk was not till" within the list few years that the question of strains in ships was really taken into consideration, and it may be said that the first attempts in this direction were made not by shipbuilders or naval architects, but by shore-going civil engineers, who pointed out the Tesemblance of a ship to.a loaded girder, Lately, both shipbuilders and he surveyors for the various classifying offices have occupied themselves unch with problems of the same nature but an inherent defect seems to exist in most of their calculations, namely, too great a tendency to reduce them toa rale of thumb. It is well known that the official calculations for registered tonnage represent very inadequately the real storage capacity of a ship, and that much ingenuity is exercised in building vessels, so that this discrepancy shall be a maximum. It seems at the first blush an easy thing to ascertain the entire contents ofavessel; and, doubtless, were the actual contents made the rule for registry, surveyors world soon light on methods approximating sufficiently near to the trath. At present, hard and fast rules, which give in certain cases approximation, but in others differ widely in their results from the actual capacity, are made the basis of measurement. Again, with regard to the strength required in the various portions of a ship there will naturally exist difference of opinion between the rules laid down by the classifying officers, and those likely to find favour with the ship-builder. The former will naturally favour rules which he knows from experience will give the requisite strength, even at the expense of a somewhat excessive amount of material, while the latter will endeavour as naturally to reduce the amount of material required to a minimum consistent with his ideas of strength, Were the strains to which a ship is liable, as capable of rigid demonstra. tion as those appertaining to engineering works on shore, the settlement of these differences would be a comparatively easy matter. Unfortunately, naval engineers have not yet decided on the abc of the art, so that calculations of strains are differently applied, and often on mere abstract rales. The ship-builder with justice says that the rules of the classifiers compel bim frequently to uso a superabundance of material in portions of a ship where strength is not actually needed, and that this extra weight of material is in itself an evil, as actually tending to weaken the vessel as a whole. The classifier says that in some possible cases such may be the fact, but that is rules are the result of a more practical and extended experience than falls to.the lot of the ship-builder, and that in any case it is inadvisable when circumstances vary so much to run the risk of too great refinement in calculation. The invariable load-line is again a subject of a dispute of a different nature between the ship-owners and the public. The former resist its being made compulsory, or even introduced as an element, while the latter consider that one of the greatest advances towards safety would thereby be made. As with all other hard and fast rules attempted to be applied to shipping, there would possibly be really little gained in the end. Ifa ship were to be prevented loading over her load line, the ingenuity of builders would be devoted to reducing her strength above what was needed for this line, to the lowest limits; and to do this the present rales for registered tonnage would probably be found to have a detrimental effect. Against this, it is suggested that the actual displacement of a ship should be taken as the basis for the registration of her tonnage, and that as economy of materials in the case girder is frequently sought by increasing its depth, so economy of materials might in this case coincide with greater height of freeboard, and therefore extra safety. Doubtless, height of freeboard is one of the great elements of safety; but the result of making the displacement of a ship the test of her registered tonnage, would be to increase the economic temptations toa reduction in the scantlings of the materials of which she is to be built, Altogether the matter is so beset with difficulties, and the conclusions arrived at for the present are so inconclusive, that we shall probably have to wait many years before any definite action is taken, 'THE MUNICIPAL BUDGET, The Budget for 1875-6 isuota sensational one, and calls for little comment. The purchase of the Tunsin property has to be completed during the year, but the issue of debentures for the purpose was sanctioned by Resolution XI, passed at the Ratepayers' meeting in May last year, Tls. 76,000 is asked for Public Works, and we believe with the Council that that sum can be well spent. Among the chief proposals are a now bridge across the Defence Creek to the Sinza Road, a new bridge on the Seward rond, and cost of anew bridge over the Yang-king-pang at the Bund; Tis, 3,000 bunding Yangking-pang creek between Shantung and Fohkien roads; a now drain in the Chekiang road, from the Hupeh to the Nanking road; a new iron pontoon, 2,800; Public Garden, including Tie. 600 for a new pavilion, Tis, 1,500; the extension of the Alpha Farm road to the Jessfield road Tis, 1,100, of the Cemetery road into the Sikaway road near Overweg's bungalow, Tis, 2,000, and of the Seward rond Tis, 2,000, Tis, 8,000 Office expenses, and Tis, 29,000 for ordinary repaira to roads, go to make up the total. The purchase of a Gatling gun, instead of the present unwieldy howitzers, proposed, and will no doubt be sanctioned.
The Report bears so much upon the estimates, that the two need to be taken together. ft contains a vast deal of matter (especially correspondence) which has been already published among the Minutes of Meetings; but there is a residue—when one can disentangle it—of considerable interest. It is remarked, for instance, at the outset, that a saving of Tls. 10,000 has been effected on the ex: penses of the staff since 1873; the fact will be noted with satisfaction, and we believe further effort in the same direction will be welcomed.—The community are indebted to Mr. Thorndike for having built and handed over to the community afoot bridge over the Soochow creek at
Text read from the printed page and cleaned; old type leaves the occasional error.