S18 Mr Menteath on the Geology of Nith&dale. 



tained by borings in different parts of the basin, the thinnest is 

 only a few inches, and the thickest does not exceed five feet. 



At the north-west corner of this basin, a kind of coal is found, 

 which is considered of a superior quaUty, and is chiefly em- 

 ployed by blacksmiths. A small deposite of limestone, with coal, 

 occurs near the Menock, and appears separated from the coal- 

 field of Sanquhar by a ridge of greywacke. It is of such an 

 impure quality as to forbid its use in agriculture. The ochry 

 sandstone of the coal-field occurs on both sides of the Nith. 

 That which is on the east side of the river is of a bad quality, 

 hardly turning wet ; but that which is found on the west side, 

 as near the mouth of the Youchan, of a yellow-whitish colour, is 

 an excellent building material. 



Some traces of iron-ore are observed near Crawick Bridge, 

 but as yet this ore has not been turned to account. 



The soil of the valley of Sanquhar is clayey, partaking of all 

 the properties of that which usually lies upon the coal formation. 

 It is stiff, tenacious, and impervious to water, requiring much 

 drainage, and much liming, to loosen its texture, and fit it for 

 the growth of good herbage. It is, however, distant from lime, 

 a circumstance which has hitherto retarded its improvement. 

 There is little or no wood in this valley, which makes the cli- 

 mate bleak and the scenery uninteresting. 



The Sanquhar coal formation, though of no great extent, has 

 long supplied a considerable range of country, as it has afforded 

 a principal part of the fuel of Dumfries and the neighbour- 

 hood *. But, it is probable that in future the extension of market 

 of the Sanquhar coal will not be increased, the Ayrshire coal 

 being now accessible, and the lower part of Nithsdale deriving a 



• That this coal-field, though of but very limited extent, is fitted to sup- 

 l).y the district in which it is placed for a very long period, a short calcula- 

 tion will be sufficient to show. 



It has been stated, that the coal-field of Sanquhar is about 8 miles long, 

 and scarcely 2\ in breadth. This will give in all about 20 square miles, or 

 13,000 square acres. Now, the seams of coal, which are twelve in number, 

 as has been ascertained by accurate borings, amount in all to only 18 feet in 

 thickness. But of these several are only a few inches thick ; and the four 

 workable seems scarcely amount to more than 15 feet or five yards. Taking, 

 then, the workable coal at this thickness, or nearly so, it will give us in each 

 acre 24,200 cubic yards of coal, or in all 314,600,000 cubic yards. But each 

 cubic yard of coal, as I have been informed by an experienced engineer, Mr 



