A HISTORY OF NORTHAMPTONSHIRE 



stone, hard, sometimes blue-hearted, semi-crystal- 

 line, fossiliferous limestones, which will take a 

 polish like marble — Weldon marble — but owing 

 to irregularity of lines of cleavage, often not seen 

 when the stone is got, they are unreliable for 

 building purposes, and are not worked much. 



The ' rag ' beds seem to run anyhow, so that 

 good freestone may occur at a higher or lower 

 level, be thick or thin, or be above or below 

 patches of ragstone. The rag may be used for 

 work where hardness is the chief consideration, 

 for road-mending, steps, and walling. 



Commonly, freestones are quarried in large 

 blocks and allowed to season, and are sent to 

 their destination to be cut up there. There are 

 advantages, however, in shaping the stone for its 

 intended use in the ' green ' state — that is, as soon 

 as possible after it is quarried, because then, pre- 

 suming the stone may be relied upon to stand 

 frost, the so-called ' quarry water ' in the stone, 

 highly charged with carbonate of lime, gradually 

 evaporates and leaves on the surface of the stone 

 a fine deposit of crystalline carbonate of lime, 

 which is decidedly protective. After the stone 

 has once dried fresh surfaces will not have this 

 protective coat. 



Great Oolite Limestone. — The Great 

 Oolite limestone rock has been used for building 

 purposes from one end of the county to the 

 other, near to where the rock occurs superficially, 

 and yet it is mostly a very inferior stone for the 

 purpose. It is an irregular shelly limestone, often 

 brashy, seldom oolitic, and after weathering, the 

 shell fragments, being less easily attacked than the 

 mass of the stone, often stand out in relief. As a 

 rule it must be built up as it lies in the ground, 

 and even then the edges of the stone weather so 

 badly that in a house-front of this stone in good 

 repair, about as much mortar as stone is seen, 

 and this feature alone generally serves to dis- 

 tinguish a Great Oolite limestone building. 

 Still, whole villages are so built, and they look 

 very bright and tidy. 



Notwithstanding the generally inferior quality of 

 the Great Oolite limestone of Northamptonshire 

 for building purposes, and its extremely limited 

 use at the present time, certain quarries acquired 

 a considerable amount of notoriety in the past, 

 as Culworth, Blisworth, and Cosgrove,' and we 

 may presume that they deserved it. Blisworth has 

 yielded a freely working oolitic limestone," which 

 was sawn up and faced for flooring, window-sills, 

 chimney-pieces, and other purposes. The same 

 quarry also yielded ' Pendle,' that is to say flaggy 

 beds, useful for rough building work. As red 

 Northampton sand and white Great Oolite lime- 

 stone, more or less suitable for building purposes, 

 occur near together at Blisworth, there may be 

 seen at that village houses built of alternating 

 layers of these two rocks. 



' Morton, op. cit. 1 08. 



■ Sharp, Quart. Journ. Geol. Soc. xrv'i, 378. 



At a few places in the north-easterly parts of 

 the county the Great Oolite limestone may be 

 worked as a freestone. Stone from Oundle and 

 Geddington Chase has been so used.' 



The Cornbrash has been used as a building 

 material for rough work, such as walls, but to a 

 small extent only. 



MARBLE 



Marble. — Certain compact, hard, shelly beds 

 in the Lower Lias, Lincolnshire limestone and 

 the Great Oolite limestone have been polished and 

 used as marbles. 



Lower Lias Marble. — It is recorded that at 

 Watford, north-east of Daventry, a shelly lime- 

 stone on a similar horizon to the so-called 

 Banbury marble,'' i.e. near the top of the Lower 

 Lias, has been dug and polished for marble. 



Weldon rag has already been mentioned as a 

 stone which will take a good polish, and can be 

 used as a marble. 



Great Oolite limestone can sometimes be used 

 as a marble. Raunds ragstone and Stanwick 

 ragstone, bluish grey shelly limestones resembling 

 forest marble, were once rather noted, and have 

 been used for chimney-pieces, for monuments 

 in churches' and other ornamental work, 

 after polishing. A similar hard, blue, shelly 

 limestone used to be quarried around Castor and 

 Peterborough, and at Alwalton, just over the 

 borders of the county, but is lacking in dura- 

 bility. It was known as ' Alwalton marble,' 

 and was used in the Early English portions of 

 Peterborough Cathedral as a substitute for 

 Purbeck marble in the small clustered columns 

 which characterize that style.^ 



SLATES 



DusTON Slates. — The thin, flaggy, calca- 

 reous beds of the Northampton sand, still 

 largely used in and around Northampton for 

 building purposes, and known as ' White Pen- 

 die,' have also been used for roofing purposes, 

 and were sometimes sold under the name of 

 Collyweston slates. They are never used now. 

 At New Duston there is a field known as 

 ' Old Slate-quarry Close,' and in the middle of 

 a small spinney in this field is a deep depression, 

 where at some unknown time in the past slate 

 was obtained in much the same way as Colly- 

 weston slate now is, by ' foxing' — that is, by sink- 

 ing shafts and quarrying the stone required by 

 means of adits. This has been ascertained by 

 more recent excavations on the same site.' 



' Judd, Geol. of Rutland, 214. 

 ' Woodward, Jurassic Rocks of Britain, iii, 297. 

 'Morton, op. cit. 107. 

 * Judd, op. cit. 202. 



^ Sharp, ' The Oolites of Northamptonshire,' in 

 Quart. J cum. Geol. Soc. xxvi, 371. 



302 



