4 CHESIL BEACH. 



tlie waves to lift the big stones, and where is the east wind that 

 can take them back in sufficient numbers, or to a sufficient 

 distance, to compensate for the movements already effected ? 

 Year by year and century by century the process goes on, and 

 seems likely to continue so long as the present equilibrium is 

 maintained. Without doubt there are other factors accountable 

 for the supply of large pebbles at the Chesilton end, such, for 

 instance, as the limestones and cherts of Portland origin. The 

 former are frequently of considerable size, but they can hardly 

 stand the wear and tear of a beach life for very long ; in the 

 struggle for existence the flints and quartzites are bound to have 

 the best of the day. 



Sources of Supply. — Having considered the subject of grading, 

 so far as the action of the wind-wave is concerned, it may not 

 be uninteresting to pass in review another important factor in the 

 natural history of the Chesil Beach, viz., the soiirccs frovi which 

 the shingle is derived, and, in so doing, we are bound to glance at 

 its geological history. The grading action already claimed for 

 the wind-wave would be seriously interfered with if there was a 

 large supply of fresh material from beyond Bridport. But here 

 Dr. Vaughan Cornish tells us that the supply of large pebbles is 

 for the most part cut off by the projections of Golden Cap and 

 Thorncombe. Perpetual attrition, then, without material renewal 

 from the western beaches, must partly account for the very small 

 size of the pebbles near Bridport. From this place to Abbotsbury 

 the beach is attached to the shore for a distance of about eight 

 miles, but, as the cliffs are mainly of Jurassic rocks, yielding 

 nothing harder than calcareous nodules, these soon pass away 

 and leave no mark. From Abbotsbury to Chesilton the beach 

 becomes a bank, isolated by the Fleet on the landward side, so 

 that no supplies are obtained from this quarter. 



Before we come to Portland, then, there remains only the sea 

 as a possible source for additional pebbles. For my own part I 

 entertain no doubt that the storm-waves are perfectly capable of 

 bringing pebbles to the beach from any part of West Bay, 

 supposing them to be there ; but soundings in a great majority 



