president's address. 15 



the quarry, of scantlings, squared to order, per foot 1 Price of 

 wall-stone (if any), at per ton 1 Description, extent, and cost of 

 carriage to London ? Cost of plain work, per foot, at London 

 wages ? Cost delivered in port of London ? 



General Remarks. — If employed in Roman works, and where? 

 Names and dates of buildings, ancient and modern, wherein 

 employed, and present state of the stone ? 



The following particulars relating to the Magnesian Limestone 

 from Bolsover quarries, near Chesterfield, in Derbyshire, convey 

 an accurate view of the qualities of this building stone — they 

 are taken from the report of the above-named Commission : — 



"The component parts are chiefly carbonate of lime and carbo- 

 nate of magnesia, semi-crystalline. The colour, light yellowish 

 brown. A cubic foot in its ordinary state weighs 151 lbs. 11 oz. 

 The workable stone is 12 feet in thickness, and is in beds varying 

 from 8 inches to 2 feet thick. Blocks of 56 cubic feet can be 

 procured. The cost at the quarry, tenpence per cubic foot ; cost, 

 delivered in London, two shillings. 



"A cube of 2-inch sides weighed, in its ordinary state, 489 8 

 grains; when well dried, 4881*4 grains ; when saturated with 

 water, 5042 grains (absorbing 160'6 grains of water, or "079 part 

 of the whole bulk). Specific gravity of dry specimens — 2*316 ; 

 of the solid particles, 2'833." 



A very valuable paper, on building stones, was read by Mr. 

 C. H. Smith, to the Royal Institute of British Architects, in 

 February and March, 1840, and continued in April and June, 

 1844. Magnesian Limestone has been little, if at all, noticed in 

 Scotland or Ireland, and, as compared with other rocks, is but 

 scantily supplied in England. It has been so modified by 

 denuding causes as to present many scenes of great variety and 

 beauty, and its protuberances were, in feudal times, occupied by 

 the barons, either for the extensive prospects or commanding 

 situations which they afford — thus Conisburgh, Pontefract, Bol- 

 sover, Hylton, and Knaresborough Castles ; Hardwick Hall, and 

 Tynemouth Abbey and Castle, each rests either on an escarpment 

 or outlier of Magnesian Limestone. 



