THE TECHNOLOGIST. [Oct. 1, 1864. 



132 



ON THE POSITION AND MODE OF WORKING THE BATH 

 FREESTONE. 



BY J. RANDALL. 



The paper -which I have the honour to lay bofore this section of the 

 British Association has reference to two subjects, both of equal local 

 interest, the one in an economical and commercial point of view, and 

 the other bearing upon the scientific conditions, both as regards the 

 mode of working and geological positions of those beds in the great 

 or Bath oolite, which may be called the " quarry stone," and which are 

 so extensively worked in the Bath district. I purpose, therefore, to 

 divide my paper into two sections, or arrange the materials into short, 

 and yet I hope sufficiently detailed a manner under two heads : first, to 

 determine the true horizon or geological position of the workable beds 

 of this valuable freestone in the series termed the great oolite ; secondly, 

 to enter upon the mode of " working and getting " this extensively used 

 and valuable building stone. 



Geological Position. — Nowhere, I believe, in Great Britain (indeed, 

 in Europe) are the lower members of the Jurassic group of rocks so 

 extensively developed as in the Bath district, where each group seems 

 to have attained its fullest recognised development ; nowhere can the 

 whole Jurassic series be so readily studied, nowhere so easily understood ; 

 and this applies to the lias itself in its three divisions — the fuller's 

 earth (here extensively employed) ; the member of the lower oolite 

 under consideration ; and the Bath or great oolite, distinguished here 

 for its economical value, and at Minchinhampton and other places for 

 its fine and typical organic remains. Above this series, but intimately 

 associated with it, the forest marble and cornbrash are highly and 

 typically developed, succeeded by the Oxfordian and Kimmeridge 

 groups, not omitting even the Portlandian at Swindon and the Purbecks 

 of the Vale at "Wardour. To each of these may be appended import- 

 ant notes bearing upon their high importance, economically considered, 

 and which are extensively developed in the district ; but I purpose draw- 

 ing the attention of the members of this section to the Bath oolite only, 

 determining the position of that zone from which the freestone is ex- 

 tracted, and on which the wealth and comfort of the population of this 

 neighbourhood, engaged in quarrying operations, so much depend. I have 

 also endeavoured to fix, by detailed and measured sections, the work- 

 able beds of the district, and to correlate them over a considerable area, 

 useful, it is hoped, both to the man of business and the geologist. These 

 sections, which I may here refer to, are all coloured the same in their 

 respective zones, and show the importance of carefully determining the 

 place or position of the workable beds, prior to any outlay of capital ; and 

 however difficult, indeed impossible, it may be to diagnose the quality 

 of the freestone beds in depth, there can be no doubt as to their posi- 



