ST. .TLDHELM'S HEAD. ixxix. 



it was also used for lighting purposes ; but, unfortunately, the smell of the oil was 

 so offensive that the use of it was given up. And, until some chemist was clever 

 enough to discover some way of deodorising it, it would remain useless. Thus this 

 great headland was built up of these three strata Kimmeridge clay, Portland 

 sand, and Portland stone to a height of 354 feet. They saw that from the top of 

 the cliff the Portland stone broke away in great solid masses and fell down to the 

 bottom of the cliff, which was protected from the assaults of the sea by a huge 

 landslip and a mass of debris. This fall of rock was caused by the waves 

 washing away the soft Kimmeridge clay at the base of the cliff, and thus 

 undermining the foundations of the harder rocks, which had consequently fallen 

 down and formed this wild picturesque undercliff. A little further to the north 

 was Emmets Hill, 400 feet high. The highest point of the coast was Swyre 

 Head, 554 feet high, surmounted by two humps, one of which was a tumulus. 

 How, Dr. Ord went on to ask, pointing to this sectional map (the section almost 

 due north and south), did the strata become inclined and forced up in this 

 remarkable way, and how had this land upon which they were standing, and 

 which was once deposited under the sea, been raised up to the great height that 

 they found it at present ? The explanation was due to what geologists called an 

 anticlinal, a buckling up of the earth's surface, just as when an orange dries the 

 surface of the rind contracts and wrinkled. As the earth cooled down it 

 contracted and so formed the hills and valleys. It was the great Brixton 

 anticlinal, beginning at Brixton, in the Isle of Wight, and extending 50 miles 

 long. It was a hummock-shaped mass which formed the hills of the Isle of 

 Wight. When they came to the Needles they found that they had been broken 

 away by the action of the sea ; but at one time they were continuous with this 

 anticlinal of the Isle of Purbeck, the great chalk ridge of the Purbeck Hills 

 which they passed through that day at Corfe the gate cut (as the word " Corfe " 

 denoted) by the denuding action of streams in geological times. This anticlinal 

 had upheaved not only the chalk, but also all the beds underlying it. These 

 hills, on the edge of which they were standing, formed an old watershed dividing 

 the northern part of Purbeck from the southern. The sea had cut away the 

 southern half of this anticlinal and shown them how enormous were the forces of 

 denudation in past ages. The point upon which they were now standing had 

 been submerged beneath the sea seven or eight times, and had other strata 

 deposited upon it. All our rivers are now cutting away the land and taking the 

 material off, possibly to puzzle the antiquaries of future ages. 



The ACTING PRESIDENT expressed the thanks of the Club to 

 Dr. Ord for his learned and lucid exposition. (Applause.) He 

 took that opportunity of adding that the excavations at Maumbury 

 Rings were being continued that week an extra week and that 

 Members of the Field Club who were interested in the work 

 should visit the Rings and inspect the cavities before they were 



