A NOVEL BREAKWATER.

Taranaki Herald, Volume XXXIX, Issue 8800, 9 June 1890, Page 3

A NOVEL BREAKWATER.

The Secretary of State for War, says a London Daily Chronicle, has appointed a committee to enquire into and report upon an entirely new idea in breakwaters, which is about to be tried in the Bristol Channel, where the " bore " is as troublesome as the waves of the sea at its worst. It is also going to be applied at Mombasa, our new port to the north of Zanzibar. It is the invention of Mr John Lewthwaite, of Sydenham. This gentleman takes a basket and fills it with stones, that is a popular bat fairlj- correct way of describing the operation. In more elaborate language he takes a number of iron rods and lowers them vertically into the water, j tying them by cross ties and rocking i bearings. It is evident that the roughness | or smoothness of the bottom does not affect the principle, or, indeed, its application. The small resistance of the rods, moreover, allows the water to flow through the basket during construction, and when the basket is being filled with stones the resistance to the waves will increase at least as much as their force ; but if a solid casing is deemed desirable, then perforated blocks of concrete or stone can be slipped over three or four or more of the rods, down which they will slide, binding the rods into position and forming 1 , as it were, a sheathing to the basket, which can then be filled up with any kind of rubble that has a tendency to set. It is claimed that a breakwater of the size and value of that at Plymouth could be made in a similar situation for one-fourth of the coat, and without the objectionable spreading out and other features of the talus system. It is also asserted that a breakwater on the Lewthwaite system would cost less than half what the Wicklow one is costing. So far well ; but now let us glance at the objections that present themselves to the plan. First comes the obvious one, that the iron would rust rapidly in r -salt water. So it would where it was alternately exposed to air and water, but when wholly immersed iron doea not rust, even in sea water, at more than the rate of a quarter of an inch in three centuries, as may be seen from guns and anchors that went to the bottom in Elizabethan days, and were recovered in our own times. Nest, the iron rods to be used wopld probably be not less than 2i inches in diameter, so that 1500 years would be required to eat away a rod. But long before that period had elapsed the ■wash of small particles of lime in the sea and the weight of the incumbent mass would have rendered the breakwater virtually a monolith. Another objection that will occur to those who have seen fiveton blocks of concrete tossed about by even a Channel sea is that the force of the water would tear a hole so to say, in the basket, and then the whole would drop asunder. No doubt this would be so if it were not that on Mr Lewthwaite's plan the whole structure would take and spread the force of the impact on any one point of it, and thus its elasticity during construction, and its homogeneity afterwards wouli be its safeguard, so far f >as any thing of human devising can be guarded against the enormous and virtually incalculable forces of nature. Even iv the case of an earthquake there would be more chance for this breakwater than for another, and it would be obviously susceptible of easier and cheaper repair as soon as the convulsion was over, since the subsidence could be repaired by feeding material from the top bo long as the framework was not structurally damaged, and it must be clear that this framework, or the basket, will be protected from fracture by the blocks of Btone or concrete surrounding it and the blocks of stone or concrete facing it. We are not saying or assuming that the system is perfect. No doubt in the application of it many points will be discovered in which it can be improved. All we venture to declare is that it has been well thought out, and that the mechanical principles on which it is based are unimpeachable. If this opinion be that of the authorities to whom Mr Stanhope has referred the subject, no doubt a trial will be ordered at some point at which the force of water in its extremest fo/m will have full play on the edifice.

THE FEOZEN MEAT TRADE. Professor Wallace has returned to Scotland (write 1 ! the London correspondent of the Argus) thoroughly convinced of the immense possibilities of the New Zealand frozen mutton trade. He does not think much oftheprospects of the colonial frozen beef trade, but scarcely regrets this, as he holds that mutton is the natural product of the Australasian colonies, as beef is the natuial product of North America. He is endeavoring to combat the impression that is still abroad that even the best of New Zealand mutton is far .nferior to that produced in the United Kingdom. He emphasises the great natural advantages wnicj New Zealand enjoys for the production of food for stock, and also mentions that imported animals exhibit a tendency to extra vigor of growth when introduced to the colony. He shows that great as has been the development of the trade in frozen mutton, New Zealand can still considerably increase the supply of meat, and afford to sell it even as low as 3d per lb rather than discontinue the trade. In conclusion, Professor Wallace asserts that a close study of this great question of meat supply can lead up to only one conclusion — viz., that it is on the eve of a wide though possibly gradual expansion. He anticipates a substantial increase in imports of the frozen mutton from Australasia — frou New Zealand in the first instance, but ultimately from Australia, in spite of the rapid growth of her population. H« congratulates the British workman upon hia good fortune in being able to secure lis meat supply so cheaply, and advises the British fanner to begin to lay his plans to meet the reduction in the price of his home product, which appears to be the most natural r suit of the growth of the foreign trade.