350 



KNOWLEDGE & SCIENTIFIC NEWS. 



[February, 1906. 



sequent partial downward movement, this was not suffi- 

 cient to counteract the former upward movement. The 

 result is seen in the raised beaches and rubble-drift 

 formations which have from time to time been 

 described. The Briijhton cliff formation is one of the 

 best examples ol this kind. The formation occurs at 

 the east end of the town, and owiny to its nature is 

 liable to constant f;dls. Thus fresh sections are 

 frequently being- exposed. At the present time, the 

 lower portion of the cliff consists of about ten feet of 

 chalk. Upon this chalk rests about eight feet of beach. 

 This beach was sorted in the same w-ay that modern 

 beaches are sorted now, so that we find upon the chal'.; 

 a g-ood deal of sand and small pebbles, and these in- 

 crease in size upwards, until large flint boulders com- 

 plete the higher portions of the beach. Although the 

 beach is mostly of flints, it also contains a few rolled 

 granite boulders and rounded lumps of red sandstone. 

 Owing- to lack of cementing material in the beach, 

 it is constantly falling on to the lower beach, and cave- 

 like holes are formed. Then, in the course of time, the 

 rubble above it, having lost its natural support, falls 

 on to the beach below, and is rapidly carried away by 

 the sea. The rubble forms the remainder of the cliff. 



This diagram shows that the Channel formerly extended further in a 

 northernly direction than now. (.-1) Raised Beach. (Bi Rubble-drift. 

 Brighton Beach. 



It is of a brown colour, and contains numerous rounded 

 and sub-angular pebbles of chaJk and flint, varying 

 very much in different parts. It was in this rubble-drift 

 that Mantell found remains of Elephas primigenius, and 

 hence the name of Elephant Bed sometimes applied to 

 it locally. Rhnwceros tichoriniis, Cervits elaphas. and 

 Hippopiiamus major were also found. 



The nature of the animal contents shows that the 

 time ol its formation (Pleistocene), although geologi- 

 cally of fairly recent date, was yet far removed, if one 

 counts by years, from existing times. The upward 

 and then the partial downward movements which have 

 since occurred, have now completely come to a stand- 

 still, but the denuding action of the sea continues, and 

 this in so porous a material as the rubble-drift is aided 

 by sub-aerial denudation. Where the coasts are 

 formed entirely of chalk, erosion by the sea is not so 

 marked, although it is far from being negligeable. But 

 when we look at our eastern coasts, and consider the 

 fragile nature of the material of which our cliffs are 

 there formed, we almost wonder that coast erosion has 

 not been more marked than it has been. The boulder- 

 clay cliffs of south-eastern Yorkshire render that coast 

 peculi:u-ly liable to denudation. The inlet of the Wash 

 was brought about by the friable nature of the strata 

 when once the chalk had been breached. The glacial 

 and crag cliffs of Norfolk and Suffolk, and the London 

 Clay cliffs of Essex all afford yielding material to the 

 inroads of the sea. On the north of Kent, the London 

 Clay is constantly slipping into the bed of the sea, 

 together with other loosely-accumulated material of 

 tertiars' age. 



When one looks at a map of our country, one cannot 

 help being struck with the fact that it is not a little 

 remarkable that the great bulge of the east c(ViSt is just 

 in those parts where the coast-line is least protected. 

 Our oldest and most indurated rocks are, on the n'hole, 

 on our west coast.s. In general our strata dip from 

 west to east, and this has been brought about by a 

 tilting movement, which has exposed the edges of up- 

 turned rocks of older date, as one proceeds westwards. 

 ITie coming oi the North Sea may have been materially 

 assisted by this movement, and since its advent, the sea 

 has steadily continued to w-ork backward, until, in- 



\ 



Diagram showing the progress of coast erosion and the formation 

 of cliffs on the East Anglian Coast: dip greatly exaggerated. 



Stead of breaking on a shelving strand, as it would have 

 done at A, it has, by ceaseless erosion, produced the 

 cliff at B. This is, in effect, the condition in which we 

 find the cliffs in East Anglia. As a matter of fact, the 

 \ ery existence of sea-cliffs is evidence of erosion, 

 whether the cliffs be formed of igneous or sedimentary- 

 materials; but to go back to the time w-hen that erosion 

 commenced, one must go back to that time when the 

 country last emerged from the sea. The task which 

 engineers have now set themselves is to protect the 

 sliores as they now are, and from a discussion which 

 took place at a recent meeting of the Institute of Civil 

 I'^ngineers, it seems to be generally accepted that 

 defence works have, as a rule, been pushed too far 

 sea-ward, as though to reclaim some of the land which 

 the sea had already swallowed up years ago. The 

 result has been disastrous to the unprotected areas in 

 close proximity. To mention two instances only, -we 

 find the scouring out of East Wear Bay largely owing 

 to defence works at Folkestone Harbour, and the rapid 

 succession of falls of the cliffs at East Brighton are 

 directly owing to the scour of the tides after passing 

 the town's defences. Tliere has been too much of 

 the desire on the part of the local authorities of those 

 areas which could afford defensive works to benefit at 

 the expense of those owners whom it would not pay to 

 make great outlays. It is well that engineers recognise 

 this, since in their individual capacity they are responsi- 

 ble for the erection of all such defence works. 



R.oma.n Coins at Hull. 



The Municipal Museum at Hull has recently acquired an 

 extensive and valuable addition to its collection of local Roman, 

 &c., remains. 



It consists of the life work of a somewhat eccentric character, 

 Tom Smith, of South Ferriby, locally known as " Coin Tommy." 



The specimens are principally of Roman date, and include over 

 2,000 coins, nearly 100 fibulse of a great variety of patterns, several 

 dozen buckles, pins, dress fasteners, ornaments, strap ends, bosses, 

 spindle whorls, armlets, spoons, beads, objects of lead, &c. 

 Amongst the fibulae are two of altogether exceptional interest, as 

 they bear the maker's name upon them (.WCISS.V). Only two 

 e.xamples of brooches marked in this way have previously been 

 found in Britain (in Somerset), though they are recorded in France, 

 Germany, Italy, &c. 



There is also an extensive collection of pottery, including many 

 vases, strainers, dishes, &c., in grey ware, as well as many fine 

 pieces of Samian ware. 



