Oct. 1, 1864.] THE TECHNOLOGIST. 



WORKING THE BATH FREESTONE. 135 



Slaughterford valleys to Yatton Keynell, Biddestone, and Corsham. 

 The Section No. 1 gives accurate measurement and sufficient details to 

 enable a practical observer to determine the series of beds at almost any 

 point over the area above indicated, or even between the westerly ex- 

 tension of the Oxford clay line from Malmesbury to Corsham and 

 Melksham, and the valley escarpments before mentioned. It is not 

 necessary to notice the forest marble or cornbrash, which is foreign to 

 my paper, and which, although usually present, may or may not occur 

 on any special area above the great oolite proper, local conditions, 

 during deposition or subsequent denudations, having removed one or 

 the other, or both ; but everywhere, so far as I know, over the whole 

 table land do we find the coarse shelly limestones, and some finely 

 grained oolite beds belonging to the upper ragstones or highest members 

 of the great oolite. In the typical section No. 1, taken at No. 7 shaft, 

 Box Tunnel, also at the shafts 4, 5, 6, these beds occur, and were cut 

 through when sinking, and were found to be from twenty to thirty-five 

 feet in thickness, before proving the " capping " to the building or 

 " fine " beds below. At Murhill, near Winsley, these upper ragstone 

 beds are about twenty feet in thickness, and are hard, coarse, and fine 

 shelly limestones, highly comminuted in structure, and occasionally 

 oolitic. In some localities many of the beds are of considerable thick- 

 ness, and of regular and even texture, still they are too hard for those 

 purposes for which the softer, fine-grained, whiter, and more easily 

 worked architectural stone below (in the second series) are sought for, 

 and to which they are applied ; and again, they are not good weather 

 stones, but rapidly fall to decay on exposure to severe changes of 

 weather. At Upper Westwood, on the south side of the Bradford Val- 

 ley, opposite Winsley and Murhill, the beds comprising this upper series 

 are thicker and of more even texture, but as weather stones are of little 

 or no value. At Farley Down, overhanging Bathford, this upper series 

 is nearly thirty feet in thickness, composed of coarse shelly limestones 

 at the top, with hard and soft ragstones down to the capping of the fine 

 " building beds " below. At Combe Down and Odd Down the beds 

 closely resemble those of Farley and Box, and approximate in thickness. 

 Thus we may examine detailed sections of the upper series at Murhill, 

 Farley, Westwood, Coombe, and Odd Down, and the Box district gene- 

 rally, but the beds at neither locality are deemed of sufficient value to 

 work for transit as a building stone. 



The Second or Middle Series. — Succeeding the ragstones above men- 

 tioned, and commencing the second series, there appears to be every- 

 where a peculiar bed extending over a large area, termed the " cover," 

 or capping, varying in thickness, but generally hard in texture ; this 

 forms the roof, or ceiling, to the fine economical building freestones 

 below, and over which it lies, and is a marked feature in extensive un- 

 derground workings, both for its horizontal extent, application, and im- 

 portance as protection to the workmen, and as commencing the second 



