IT is only to be expected that the sub- ject of the erosion of the coast, which in other words means the encroachment of the sea, should be one of considerable interest to the ROYAL NATIONAL LIFE- BOAT INSTITUTION. The nature of Life- boat work demands that in many cases the Life-boat houses must be erected as near to the sea as possible, whilst ex- pensive slipways and other means for launching have also to be provided to put the stations in as efficient a state as possible. Any variation in the coast naturally alters the circumstances in which a life-boat is launched; not only does the erosion of the coast affect the launching conditions, but also accretion makes difficulties; however, this does not so frequently cause trouble as erosion. In selecting sites for Life-boat houses therefore it is of the utmost im- portance to study what has taken place, what is likely to be expected from the action of the sea and what sea defence works may be in contemplation in the neighbourhood. There are many parts of the coast of Great Britain and Ireland where to erect anything of a so-called permanent nature, such as a steel or timber slipway, would be simply throw- ing money into the sea. Take for in- 4stance the Holderness coast in York- shire, between Bridlington and Spurn • parts of this are being swallowed up by the sea in exceptional years by as much as 20 feet a year. Much of the coast of Norfolk and Suffolk is suffering in a like degree. At Pakefield (Suffolk) in 1884 the Life-boat Institution had two life-boat establishments, a large life-boat and a small one, both in wooden houses on the sea front, with timber slips or platforms for launching over. Not only has every vestige of the houses and slipways disappeared, but many of the buildings standing some distance inland from them have also fallen victims to the inroads of the sea. The Life-boat houses at Southwold are being similarly threatened, but these are only two among many instances which might be quoted.

Sea defence works on the comparatively small scale usually carried out have any- thing but a salutary effect on the imme- diate neighbourhood. The sea is inexor- able, and if you block it out in one place it will find its way in at another; con- sequently a spot which has had a goodreputation for withstanding the sea may, as the result of neighbouring sea defence works, have its character completely altered. Some of the boat- houses of the Life-boat Institution have suffered from this cause.

Sea defences, to be of any good, must usually involve considerable outlay, although if the mischief be taken in time the outlay is of course much reduced; un- fortunately, in the majority of cases, action, is not taken soon enough, with the result that, when action is taken, the depredations of the sea have made such headway that enormous sums have to be raised to provide any satisfactory check.

Another great difficulty is the lack of combined action in the owners of the coast line affected. This is not difficult to understand ; individual interests vary so, greatly that any attempt at combined action is met with so much controversial matter on account of these different interests, that it is usually doomed to failure. The result is that.

a far-seeing landlord takes time by the forelock, protects his property by groyn- ing or other means at the expense of the neighbouring part of the coast, and if a Life-boat Station happens to be on that neighbouring part of the coast, the Life-boat Institution suffers, and has to provide a new boat-house and possibly expensive launching arrangements. Care- ful as the Institution is in selecting its sites for Life - boat Stations, it will readily be seen by these remarks that it is not always possible to guard against contingencies.

The erosion of the coast, its causes and cures, is a deeply scientific subject involving the closest study. This will be gathered from the perusal of a series of articles, by Mr. R. G. Allanson-Winn, in the monthly periodical entitled " Public Works," November, 1903, to February, 1904. The writer has, it is understood, been for many years associated with sea coast protection works and has given up much of his time to the problems in connection with land reclamation and' the erosion of the coast. These articles traverse a considerable part of this important subject, and place the writer's views and theories before the public; they are instructive and conducive to thought; quotations from them will probably prove of interest to those who have not time to read the whole series.

As to the causes of erosion and accretion, speaking generally—" We have shifting winds, currents varying at different depths in direction and intensity, the daily change of the tide, the never- ceasing alterations in submerged banks, causing the currents to infringe with ever varying effect upon the neighbour- ing shores, and, possibly worst of all, we have the absolutely indeterminable con- currences of exceptionally high tides and storms. Startling indeed are the results of these storms on occasions, and the task of collecting all the data really necessary before setting to work often seems well nigh hopeless. In no two places are the conditions precisely similar, and a very great deal of judgment is necessary to avoid a use- less expenditure of money." There is, apparently, no systematic method adopted by the Government or any public body for collecting all the necessary information as regards the above, and keeping a trust- worthy record of the changes annually taking place round our coasts; the writer of these articles recommends that a Department should be formed among whose duties should be : " (1) The systematic and repeated taking of sections (over the same lines) on all shores, as well as contours of high water, low water, and mean sea-level lines; (2) The taking of soundings; (3) Calculations based on observations respecting the varying rates and direc- tions of currents at high water, low water, and mean sea-level; (4) Obser- vations as to the velocity and vis viva of waves ; (5) Observations on the travel of beach sand and other material, especially round headlands, piers, break- waters, and across bays and estuaries ofrivers." It would appear that in Germany this matter is taken charge of by the State, and there is in Dresden an experimental laboratory called the " Flussbau Laboratorium," at which may be seen models of the big rivers, and the Professor is enabled, by regulating the supply of water and by the introduction of coloured sands, to show what happens in time of flood or the reverse, and by the introduction of miniature break- waters and other obstructions, or by cutting channels, good ideas can be formed of what really might take place.

At present a committee of the British Association has arranged, by the assist- ance of the Admiralty, to obtain returns of changes noted from time to time in the shores of the several coastguard districts of any protective works which may be carried out, and of the effects produced by such works. This, the writer of the articles says, does not go far enough, but is a step in the right direction. Most people probably are under the impression that this subject is covered by the labours of the Hydro- graphical Department of the Admiralty; but—"the hydrographical surveys con- stantly being carried out by the Lords Commissioners of the Admiralty are of great value for the detection of banks in process of formation, and other changes which are taking place on the sea bottom. There are, however, only ten vessels employed in this gigantic task, both in home and foreign waters, and it can be readily understood how slow must be the process." One cannot help agreeing with the author that an extension of these hydrographical sur- veys, embracing also the question of the actual foreshore alterations and the taking of records, would throw a good deal of light on the whole subject of foreshore protection.

It is interesting to learn that from the author's observation when important works are about to be started "the greatest attention is bestowed upon the surface currents, and experiments are conducted with floats, etc., whilst the material bearing and material shifting currents near the bottom are, by comparison, neglected." Some very interesting details are then given of the effects of the erosion taking place in deep water below low water mark, and the author states " that heavy material is often moved in depths of 10 fathoms is now no longer a matter of doubt— it is a proved fact." In referring to the " march of the sea," as it is occasionally recorded by history or tradition—" An examination of the records of several places on the east coast of England tends to prove that in the olden days towns and villages stood directly over the site of the present 5 fathom line, i.e., there is now a depth of 30 feet of sea water where formerly dry land above was to be found. Here again we observe the advance of deep water, and since it is improbable that the general inclinations of the shore and sea bottom have very materially altered since the old days, we may fairly suppose that when those ancient towns existed the then 5 fathom line was a mile or so out to sea, i.e., two miles from the pre- sent coast line." Among agencies causing erosion—" It is also known that marine forces, shell- fish, fec., are constantly at work dis- turbing material which is then more readily moved by storms and currents.1' The movement of material by fresh water springs is also a prolific cause of erosion.

To sum up, the causes of the erosion where the coast material is of a soft and easily eroded nature would appear to be— 1. The surf and wave action aided by currents on the visible shore be- tween high and low water marks.

2. The erosion going on below low water level, perhaps many miles distant and in 5 to 10 fathoms.

3. The action of countless forces, shell-fish, worms, eels, &c.

4. The action of submarine springs.Nos. 1 and 2 being the principal causes, 3 and 4 contributory causes.

When we come to the remedial methods advocated by Mr. Allanson- Winn, we are on ground somewhat controversial, and into which it is not the province of this article to follow. Mr. Allaiison-Wimi is a great advocate of the use of the " Case" groyne, and in support of his views he gives interesting examples of their suc- cess and comparisons with other methods.

In alluding to them he remarks, " But the groynes, useful though they have been, will not work miracles: they will not affect the alterations in the sea bottom beyond their reach and 'out of range' so to speak." At considerable length the writer of the articles in question expounds his theories as to deep water currents and the travel of material held in suspension and heavier material moved along the bottom, and deplores the want of absolute knowledge on the matter.

Perhaps, however, the most interest- ing chapter is that devoted to " The Collection, Distribution, and Abstraction of Natural Defences." With regard to the removal of Natural Defences— " The question of the wholesale removal of the foreshore material for builders' purposes or for ballast is one which is being constantly brought under the notice of those engaged in the protec- tion of the coast line," and the author instances Bray, near Dublin, " where the foreshore owner is removing shingle and gravel at the rate of about 10,000 tons per annum." It is not unusual, he states, to find the authorities at seaside watering-places in a state of considerable anxiety about the dis- appearance of " beach " from their fore- | shores, and yet to find the same people are selling the " beach" for building or other purposes at a considerable ! profit, the idea being prevalent that the I next tide brings in as much as has been taken away ! This certainly seems to be a practice to be discountenanced, and in many instances latterly the Board of Trade has stepped in and stopped the abstraction of the natural defence. To quote again—" When we consider that 10,000 cubic yards of beach—quite a common amount to be taken away from a foreshore in the course of a year— represents a bank 15 ft. high, 30 ft.

wide, and 600 ft. long, and that in most cases this can only be replaced by material eroded from neighbouring cliffs, and what is carried from deep water during storms, we can arrive at some idea of the trials of a foreshore engineer who is endeavouring to collect, arrange, and retain material for the protection of the coast line." The whole subject is one of deep interest and national importance. Acres and acres of the country are being con- quered by the sea annually, and though much is done it is but a drop in the ocean.

To stop the ravages done by the sea is not in human power, but that more might be done than is done must be patent to all who have in any way been brought in touch with the question, and the more the subject is brought promi- nently before the public, and the various i theories of amelioration ventilated, the ! ' more likely is it to receive the attention ! due to it..