Right on the top of this aystom, and in what 

 some geologists call the Wualden bods, and put 

 as the lowest of the cretaceous stnita, wc come 

 upon a peculiar kind of consolidated limestone, 

 made up entirely of the shells of a species of 

 fresh water snail just hard enough to take a 

 polish. This is known as " Bethersden marble," 

 and may very often be recognised doing duty in 

 Kentish villages as a chimney piece, or in the 

 churchyai-ds as a headstone. The form of the shell 

 is most distinct. 



Just below this point we find slielly limestone 

 composed of a mass of much smaller shells kno^vn 

 as " Paludina," a " marsh " snail. 



It occurs in layers not exceeding a foot in 

 thickness and was peculiarly atlapted for long and 

 slender shafts or columns, so characteristic of the 

 early English style in chiu'ch architect lu'e, giving 

 gi-ace and beauty to oxir own Cathedral. 



The marble takes a good polish, but from the 

 fact that in the shape of columns, it cannot be set 

 « in its natural bed, the sides in course of time give 

 way along the planes of bedding, and the shaft or 

 column ceases to be round. 



Before going lower down, we must mention the 

 beds showing well round Hythe, and known as 

 " Kentish Eag." These occur in a limited area in 

 the lower greensands of the Cretaceous system. 

 Being extremely tough, and of good lasting nature 

 it is well adapted for building where the initial 

 expense is borne by the many, or for structures of a 

 public nature intended to stand the elements for 

 centiu'ies. Our own grand old AVestgate is a 

 woi-thy example, and stands to-day, a memorial 

 not only to Archbishop Sudbury who built it, 

 chiefly at his own costs and charges, but to his 

 wisdom in making selection t>f so good a niatex'ial. 



Previously to 1623 Pox'tland stone does not 

 appeiir to have attracted much attention. 



In 1600 Inigo Jones restored a portion of old St. 

 PaiU's, which was originally built of another 

 " wonder in lime " from the Midlands, an oolite 

 atone known to-day as " Weldon." Although the 

 quarry owners claim this stone to be " very dur- 

 able," hardening under exposure, and able to 

 resist frost and water, we take it, that they mean 

 it will do all this perhaps for a little longer period 

 than some other limestones. That it did not last 

 in its early beauty without showing signs of decay 

 and collapse, is evident froni the fact that just 

 before the great fire of London, it was necessary 

 to case the walls, and had it not been for the forest 

 of scafliolding that encircled the old Cathedi-al at 

 the time of the great fire, it might have been 

 standing to-day. The scaffokling caught alight, 

 the Cathedi-al was doomed, and Wren's master- 

 piece occupies the site. The stone chosen for tho 

 restoration, was from this Portland bed, and when 

 Cliristopher "Wren came i\pou the scene, he decided 

 to use the same kind of stone, and we must admit 

 that this Portland Oolite is most suitable for 

 massive structures in classicalstylos.UkeSt. Paul's 

 Cathedral of to-day. 



The quarries from which Sir Christopher Wren 

 obtiiined the Porthvnd stone whicli ho employed 

 liave been long deserted, the reason assigned l»eing 

 that the stone is a little harder, and thereby more 

 expensive to work. There is this conseijition about 



it ; when the sofier beds fail, tlu- harder l>eds will 

 be wanted, and they will not spoil in the keeping. 

 It is most interesting to note the great local 

 convulsions in the earth's crust at the time when 

 the strata now referred to, were laid down. 



The Purbeck marble is a mass of fresh water 

 shells, and immediately below, lies the Portland 

 stone, full of fossils of animals that lived in the- 

 salt water of the ocean. 



Geologically speaking, it was not so very long 

 ago that England was joined to the Continent, 

 and just across the Channel is found that finest 

 grained of all the oolites that was used for the 

 fabric of our own Cathedi-al and for nearly all the 

 monastic buildings in this corner of the country. 



Caen stone will last, and has lasted for several 

 centiuries after leaving its native bed, but the 

 gases emanating from coal fires, have a distinctly 

 disintegrating eEfect upon it when exposed to the 

 elements, causing it to crumble and disappear. 



For internal decorative work we have not far to- 

 go to see how admirable a stone it is, and the Caen 

 carving inside oiu* Cathedral shows again — the 

 '* wonders of lime." 



So far as we can gather from ancient customs, it 

 has always been a laudable characteristic to study 

 economy, so that when we look upon our noble 

 Cathedral, wliat we were intended to see is stone,, 

 but where the eye of the casual observer does not 

 penetrate may be anything. The fact that the 

 " Cxods see everywhere " was all very well for the- 

 builders on the Acropolis of ancient Greece, but in 

 mediaeval times the order was for a facing of 

 stone without and a core of chalk, flint, sandstone, 

 or anything fairly hard and held together as a- 

 kind of concrete. 



To wit— the Angel Steeple or Bell Harry Tower 

 of our Cathedi-al is really built of good, sound,, 

 honest brick, which anyone can see who ventures 

 up the belfry spiral ; no bricks appear outside, but 

 in some places a few inches of Caen stone skin, or 

 face, or crust, make this venerable tower so beauti- 

 ful in its proportions, a " wonder in lime " that all 

 the world wants to behold it. 



The restoration of oiu- Cathedral, now in process, 

 has been carried out with a shelly, granular oolite, 

 known as " doulting " stone, the colour of which 

 varies from cream to light brown. It is a 

 promising and compact limestone, and it is stated 

 that the stone, which is free in working, is very 

 durable and uniform in its textiu'e. 



Of Bath stones on the market there are a dozen 

 kinds, and twice that number of names. Among 

 other oolites of note is that fine grained limestone 

 known as " Ancaster," of wliich many of the 

 Lincolnshire chiu-ches ax'e constructed. Chibuark 

 and Ham Hill are great favourites with some 

 architects. 



The creamy-pink oolite stone known as 

 *' Ketton," and which the local masons call "roe 

 stone," was largely used in the restorations of 

 both Ely and Peterborough Catheilrals. A cream 

 coloured limestone known as ** Painswick," from 

 the upper oolite, was used in the construction of 

 the Houses of Parliament. 



The lectm-er then had placed upon the screen 

 some illustrations of the gigantic animals which 

 formerly roamed the cf>untiy nnw known as Kent, 



