NEW MODE OF CONSTRUCTING BREAKWATERS.

Globe, Volume VI, Issue 643, 11 July 1876, Page 4

NEW MODE OF CONSTRUCTING BREAKWATERS.

A meeting of gentlemen took place a few days ago in Wellington, to hear a description of a new method of constructing breakwaters, invented by Mr Joseph Dyer, and recommended by Mr T, M. Hardy Johnston, 1 M. Inst. O.E. Amongst those present were the Hon E. W. Stafford, Messrs J. Kelly, Button, Kennedy, Wason. Laruaoh, Moorhouae, Carrington, and other members of the House of Representatives, as well as very many influential gentlemen of Wellington. A sectional drawing of the invention was exhibited, and to all present Mr Hardy Johnston explained details ; but the following statement, read by Mr Dyer, gives so clear a description of the that the proposals of the inventor may be easily comprehended : I, Joseph Dyer, of Wellington, claim to have invented and discovered a new and improved method of constructing seawalls or breakwaters, whereby the force of the waves is so broken and subdued that harbors of refngemay be more cheaply and rapidly constructed than has hitherto been the case. I declare that to the best of my knowledge and belief, founded upon enquiries made, this invention is entirely original, and that no letters patent have ever been issued or applied for wherein the same or similar methods of construction have either been specified or indicated. I further specify and set forth the mode in which I propose to construct such seawalls and breakwaters, to the intent that I may establish my claim to have so invented and discovered it, and I declare my intention to apply for letters patent securing to me the sole privilege of using such invention; and I hereby claim' the protection of the statute for the plan so published, for the space of v six months from the date hereof, in order to enable me to perfect the plans, drawings, and specifications, as allowed by the statute aforesaid. I therefore declare the following to be the plan and mode of construction. I oppose to the advancing wave a wall, not composed of a flat surface, which would offer resistance to its approach, but a wall composed of longitudinal iron cells or tubes, the open ends of which, closely fitted together, front the wave. These are secured to each other and kept in position by being attached to very strong screw piles, which have a vertical section of an acute triangle, so that they oppose no resistance to the attack of the wave. This wall of hollow iron cells, so attached, extends iu height from two or three-feet below low water mark to such height above high water mark as may be fgund necessary; the sectional area of these cells to be of such dimensions as may be hereafter described. These cells, so attached together, and of such length as may be found sufficient, extend backwards towards the shore at a given angle of elevation to the horizon. The sides of these cells, which may be of rectangular or hexagonal shape, converge to each other at the shore or near side of the said seawall, gradually diminishing in dimensions until the aperture at the rear is not more than one-eighth of the area of the aperture at the sea front. The interstices between the converging sides of the said iron cells are to be filled up with , cement, concrete, and the superficies of the wall so constructed will, it is claimed, form a pier or jetty that the sea cannot sweep away or pass over, but which may be used as a road or means of access for shipping, sheltered from the sea by such wall or jetty. It is claimed that the front of this wall of hollow iron cells, the sides of which are of the thinnest structure compatible with the requisite strength, will offer the least possible obstruction to the force of the advancing wave, as the open months of the cells will face the prevailing direction cf the current of wave and wind to be opposed in each specific case. It is claimed further, that the wave iu rushing with extreme violence into these partially closed and gradually rising cells will have its coherence so destroyed and cut up that it will encounter the graduated and elastic obstruction of the atmosphere contained in each of them. But the rear of the cells being partially open, the air will be expelled with more or less force, and thus tt e vast dynamical force of the water will be employed in compressing and expelling the air contained in some thousands of selfacting pneumatic breaks, and will not avail '""to disturb the surface of a harbor so protected It is claimed that this process will he far cheaper and more rapidly constructed than solid walls of concrete or a wall of masses of stone deposited in the usual form of a breakwater. It will also be apparent that immediately on the retreat of the wave the superincumbent air will rush into the orifices from which it has so forcibly been expelled, and thus the structure will again constitute an elastic atmospheric wall, against which waves may dash in vain. The general opinion seemed to be that the design appeared capable of being carried into effect, and that if it could be carried into effect, the invention would be of incalculable benefit, seeing that it is estimated such a breakwater as that proposed could be constructed at half the cost of, and in about one-twentieth the time occupied in, the construction of ordinary breakwaters. Mr Dyer was urged to have a trial made in some of the bays in the Wellington harbor.