404 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



Decemkkr, 



ENCKOACil.MENTS AND HKCES.siONS OF THE SEA. 

 (From tlie Civqiic Ports' Chrviiich.) 



A cor.RESPONDENT liaviiig, a considerable time past, mooted the 

 liitherto, we believe, unanswered question as to the causes which 

 produce encroachments and recessions of the sea, upon a line of coast 

 having nearly the same geographical bearing, and especially as regards 

 the sontli-eastern coast of England : we have delayed attempling the 

 solution (if the problem on oiu- own part, in the hope that sonip of our 

 correspondents would anticipate our labours by directing their atten- 

 tion to the subject. 



The correspondent to whom w^e have alluded, very justly observes 

 that the traveller along om- shores is somewliat puzzled t(j find a town 

 or village once washeVl by the sea, now standing two or three miles 

 inland ; and other localities, within the space of a few miles, which 

 were once at a remove from the ocean, now diminishing, by the daily 

 encroaclmients of the billows. 



Commencing with Beachy Head, we have at once an instance of the 

 latter, as formerly, springing fmni the base of the clitt' were seven per- 

 pendicular rocks, denominated the Seven Charles' ; these, in 



" The incessant war of wave and rock." 



have, for the most part, been undermined and washed away by their 

 indefatigable adversaries — the winds and the waves. Continuing our 

 progress eastward, we finil not only considerable tracts of land or 

 sward, formed upon a sub-stratum of beach, extending from the head- 

 land towards St. Leonards, a distance of about eighteen nnles; b\it 

 about midway between these towns, we have undeniable evidence of 

 the extent of the recession of the sea, in the fact, that the hill or clitf 

 upon which Pevensey Castle stands, is said to liave been washed by 

 the sea, while its perpendicular distance from the present high water 

 mark is about two miles. Bexh.ill, further eastward, may also be 

 pointed out as having been subject to a similar, though less extensive, 

 alteration of locality. The rpiestion hence arises — can a physical 

 cause be assigned for the remarkable changes under consideration? 

 We are aware of the risk we run of incurring the charge of presump- 

 tion in attempting to solve that which, as far as our reading has ex- 

 tended, we Ijelieve, has never been attempted by geographers or 

 geologists ; but years of attentive consideration to this subject has so 

 thoronghlv convinced us of tlie simplicity of the law which produces 

 the alterations in the aspect of our coasts generally, and especially of 

 the south-eastern, with which we are most familiar, that, as none of 

 our philosophical readers have come forward to explain a subject of 

 considerable interest to residents and frequenters of our shores, we 

 shall proceed with all deference to lay our opinions before the public ; 

 being at the same time open to convictioe, and perfectly willing to 

 insert in our coluums any observations either against or in corrobo- 

 ration of the view we take of the subject. 



The simple law, then, which we regard as the origin of the changes 

 in the aspect of our coast, is (lie ttnchncij of the sea to preserve its pa- 

 niliil under the infioence of the prevailing wind and current. The 

 tendency of water to find its level is universally known, and that of 

 keeping its parallel is as unquestionable, tliough less obvious to com- 

 mon observers. Were the coasts and shores washed by the ocean 

 comjiosed of the same geological substances, as, for instance, sand or 

 clay, the phenomena of the geographical changes muler consideration 

 would not occur; but it is otherwise : our coasts being diversified with 

 ridges of rocks, and with plains level with or below high water mark. 

 In the former case, the action of the waters of the channel would be 

 similar to the uniform waste of sand raised as embankments on each 

 siilc of a sloping trough, along the centre of which water was made 

 gradually to flow ; but in the latter case, which actually obtains, the 

 comparison is only maintained by supposing a number of stones or hard 

 masses were irregularly thrown into the trough, which would occasion 

 an interruption to the equable ilow of water, and have the efi'ect of 

 throwing the waters, diverted from their parallelism, into serpentine 

 courses, causing inroads upon the sand or yielding substance at the 

 sides, in jiroportion to the obstructions which they met with from the 

 hard projecting masses. Such, then, we believe to have been the ease, 

 when the shores we inhabit were separated by the effects of earth- 

 quake, or otherwise, from the opposite coast of France. The waters 

 of the channel, impelled by the prevailing currents from the Atlantic 

 and the south-westerly winds, found their parallelism obstructed by 

 the rugged inequalities of the channel, occasioned by the intervention 

 of moiuitainous ridges. Tins had the etfect of throwing the waters 

 iqjon the lowlands and coast composed of sand or vegetable earth, in 

 the same proportion as the waters were obstructed in their onward 

 flow by the causes alluded to ; and which inroads will always be found 

 to have occurred on the side of the obstructing mass opposed to the 

 prevailing momentum. F'^'om this consideration we sliould naturally 



infer that, in the early years of creation, or of the formation of new 

 marine channels, the coast scenery nnist have been even more diversi- 

 fied and romantic than it now is. hi speaking of the equal ratio be- 

 tween the obstruction of water in its current, and the incursion which 

 it makes in consecpience of that interruption, we need not merely in 

 corroboration refer to the shu|de fict that, wherever there is a head- 

 land, there is a bay, on the side o])posed to the prevailing power of 

 water ; but it is worthy of note, that luider ordinary circumstances of 

 a geological character, the proportions between the perpendicular 

 extents of promontories and their bays are distinctly and unequivocally 

 marked. By way of illustrating our subject, we will return to Beachy- 

 head in confirmation of our theory, that changes in the face of the 

 coast are occasioned by the eflbrts of the ocean to obtain its parallel- 

 ism. By comparing ancient maps of the coast with modern ones, the 

 extent of tlie alterations ettected upon the south-eastern coast will be 

 more readily perceived. We have already shown tliat the face of 

 Beachy-head has, within the memory of man, sutl'ered considerably 

 from being undermined and washed away by the sea : and could we 

 liave beheld it as it was in the times of the Romans, we doubt not we 

 should have seen it stretching out much further into the sea than it 

 now does, and the waters, obstructed in their course by its huge mass, 

 sweeping round its eastern base, forming a deep and ample port (pro- 

 bably the Anderida of the Romans), and the bay spreading its waters 

 over the level, till it washed the hills upon which Pevensy and Bexhill 

 were built.* But why has the sea receded, remains still to be an- 

 swered. We answer, simply by the gradual removal of the causes 

 which occasioned its irruptions : in other words, the liquid element 

 has, in its incessant warfare, reduced the opposition occasioned by 

 projecting masses of cliffs; these have been undermined, the super- 

 strata hurled from their heights, and after, perhaps, temporarily in- 

 creasing the obstruction, and causing a greater influx of water upon 

 the plains, which must be regarded as exceptions of the general law 

 of equalization which our coast is sustaining, these iirocumbent masses 

 of chalk or stone have been battered en detail by the merciless billows, 

 reduced to fragments, and swept by the maddening tempests into the 

 deep, or from the locality in which nature had (jriginally deposited 

 them. The headlands being thus diminished, and causing less reaction 

 of the sea, deposit after deposit of beach is made in the bays, which 

 increase in the same proportion as the neighbouring headlands wear 

 awaj'. In the course of a few years a green sward covers the beach, 

 and unless interrupted by some extraordinary circumstance, tending 

 to infringe upon the watery world, the work of decreasing the excres- 

 cencies, and filling up the indentations of the coast, is carried con- 

 tinually on by the aqueous element. 



hi concluding our observations upon this interesting problem, we 

 shall proceed to illustrate the solution, "That the mutations to which 

 our coast is subject, jirocced from the tendency of the waters of the 

 channel to find their parallel," by further reference to the past and 

 present state of the coast. Resuming our examples to the eastward 

 of Bexhill, we find that the clifl' upon which the Galleyhill station- 

 house is erected, is fast consuming away by the continual assaults of 

 the sea; and, in accordance with the law which we have jjointed out, 

 the waters which were formerly obstructed by this interposing head- 

 land, and thereby intruded with augmented force upon the level to 

 tlie eastward, so as in former times to render Bulverhithe a small 

 tributary port to Hastings, and to form a bay from that point to Bo- 

 peep : the waters, we repeat, in the same proportion as they have 

 effected their parallelism, have also left deposits of beach in the bay, 

 which tliev originally formeil. The curvature of this neighbourhood 

 is now trifling, and in a few years hence its parallelism with the .S.W. 

 will be perfectly eft'ected by the prevailing current from that quarter. 



By the consumption of tlie St. Leonards, the Cuckoo hill, and the 

 Castle clitt's, the ^ alleys at the Priory, and between the West and East 

 hills, were forsaken by the sea ; in proof of which, we need only state, 

 that in removing the Priory bridge, and in digging the foundation of 

 Mr. Jackson's house, at the end of High-street, nothing, we believe, 

 but beach was discovered — an unanswerable evidence of the sea having 

 formerly entered the mouth of Ciich \alley. We have no doubt that 

 Hastings, the Danish pirate, selected our locality as his occasional 

 rendezvous, from the circumstance of the East and West hills or clitt's, 

 which projected in the sea, forming exceUent spots for the formation 

 of his camps : and between which, at the mouth of the valley, he could 

 take refuge with his fleet of galleys, perfectly sheltered from every 

 adverse wind. 



The cliffs, immediately to the eastward of Hastings, are continually 



■ If the iiroportions tjetuceu tlu' lioadland ami tlic bay be equal, as we 

 have assumed, by measuring the distance from tlie iiresent liigh water mark 

 to the most inland extremity where beach can lie discovered, we shall he able 

 to ascertain, witli tolerable accuracy, tlie distance «hich the iiromontory for- 

 merly extended. 



