BEVIEWS. 



135 



hollow work on account of the labour involved, but for marine construction in 

 pierre perdue the whole mass of Oolite there is admirably adapted. The other 

 quarries in Purbeck furnish stone less hard than those above mentioned, but still 

 superior to the true ' Portland' in their essential characters. All the quarries of 

 ' Purbeck'-Portland are in the face of the sea chffs, the fii'st portion being cut 

 down perpendicularly from the crest, which when elfected at once by blasting is 

 termed ridding^ so as to form a platform level with the base of the merchantable 

 stone, which in most of them is afterwards extracted by driving galleries into the 

 rock, forming deep caverns, and leaving pillars for the support of the superincum- 

 bent mass. From the position of the quarries the produce can only be shipped in 

 very calm weather, so that the greatest part of the year they are unapproachable. 



" The beds, in descending order, are the ' cinder,' the ' red-head,'' thick beds of 

 shelly rock, the ' sAHmp '-stone, the ' Uue-hed,' the ' white' and ' spangle-cap,' good 

 for hme, ^pond' or ' upper freestone,' a good material for building purposes, the 

 'cap-stone' in three beds, 'Hsty,' 'middle,' and ' house cap,' under-picTcing 

 cajp,' which is picked or blown out to free the great bed of working stone, known 

 as the 'freestone' or ' under freestone.' Below this is a thick mass of rock, con- 

 taining large nodules of chert blending by concentric rings into the limestone. 

 This has never been used, but would be admirable for the pierre perdue works, 

 above refen'ed to. 



" The mode of shipping the stone from Swanage is even more primitive than 

 that employed for bringing it to the surface. There is no pier for this purpose, 

 although its constmction would be a sovuce of great profit even in the present 

 state of the trade. The stone, being carted to the beach, is there piled on the 

 bankers, as the storage quays are called ; when wanted it is handed into a cart,;the 

 cart is drawn into the water, and the stone is passed into a barge, and thence 

 again is delivered to the vessel lying in the bay. For the oolite, or ' Purbeck '- 

 Portland, it is necessary to get it fi'om the quariy in the short intervals of fine 

 weather, when it is craned into the vessel and conveyed to the bankers, where it 

 remains until it is required for use. By these cumbrous arrangements a valuable 

 and beautiful piece of beach is rendered a useless deformity for all other purposes, 

 and by this accumulation of tedious and expensive labour, some of the finest and 

 most durable building stones are prevented from being so fully employed as they 

 might be, and a great hindrance is created to the execution of architectural works, 

 for which the varieties of Purbeck and ' Purbeck'-Portland are not only eminently 

 fitted, but really superior to any other khids in the market." 



Geological Map of England and Wales. By A. C. Rams AY, F.R.S. F.G.S. 

 Local Director of the Geological Survey of Great Britain. London : E. Stanford, 

 Charing Cross. 



When we say this is unquestionably the best geological map as yet pubhshed of 

 England and Wales,* we nave said all that e\en Professor Ramsay could desire of 

 a critic, and we may fairly proceed to point out what appear to be defects. This 

 we do unactuated by the slightest desire to find fault, but simply because an 

 authoritative name will often lend an unintentional character to blemishes. 



First, then, in more places than are indicated on this map the occurrence of 

 alluvium might have been marked ; as, for instance, the Pevensey levels, on the 

 north side of the mouth of the Humber, and in the river valleys of Norfolk. 



The patch of Tertiary strata at Newhaven has been overlooked, and we should 

 have certainly wished that Professor Ramsay had dropped as obsolete the term 

 " Plastic Clav ;" for having partly adopted Mr. Prestwich's admirable grouping of 

 the British Tertiary strata, he should also have adopted Mr. Prestwich's far 

 preferable denomination of " Woolwich-beds." 



* We are not oblivious of Mr. Greenough's long celebrated map, the larger size of which gives, 

 of course, greater latitude for details. A new edition of this, we believe, is about to be published. 

 Its greater dimensions and higher pretensions will necessarily make it a more expensive work ; 

 but although it should even surpass Mr. Stanford's publication, it can never be regarded in the 

 light of a rival. 



