miners. 



350 MINERALOGY OF ARRAN. 



that case, men's wages would be running on, the machinery- 

 would be rotting, while the pit would be drowned with 

 water. 



Mr. Jamieson also states 4 the great frequency of basaltic- 

 reins as another cause, which must render the coal, if it 

 should ever be detected, of an indifferent quality, and dif- 

 ficult to work.' 

 No feasaltes With regard to the basaltic veins, I remarked it as an 



field. 6 °° a uncommon circumstance in Arran, that I could not find 

 a single basaltic vein in the coal-field, or as far as the white 

 sandstone extended on each side of it. There did not there- 

 fore appear to be the smallest ground for believing that the 

 coal was cut off, or its quality injured, by basaltic veins. 

 Mistake of the When they wrought the main seam, by digging along its 

 outcrop a large open trench, they came to the strata Avhich 

 form the steep side of the mountain, and which here rise 

 at an angle of nearly 70°. They thought the coal ex- 

 tended through the base of the mountain, and cut a mine 

 to follow it out. Had they bestowed the slightest attention, 

 they might have seen, that the strata on the side of the 

 mountain are very different from those which include the 

 coal; and that, when the latter touch the former, they 

 suddenly terminate. The strata on the side of the moun- 

 tain appear to have been of much earlier formation, and 

 they rise at a much higher angle, than those which include 

 the coal. Nor docs it appear that the quality of the coal 

 was in the least affected by its approach to the mountain; 

 for it was equally good until it was cut off. 

 Siliceous sand- On examining the strata perforated by their mine, I 

 found them to be siliceous sandstone flags, of great hard- 

 ness, and of a brownish white colour, their surfaces ex- 

 hibiting micaceous scales. They are from one to two inches 

 in thickness, and are curiously bent upwards, into the form 

 of a Gothic arch, or rather of a great many arches over- 

 lapping each other, which form the roof of their mine. 

 It was useless to follow the coal from the strata where it 

 was found, into strata so very different, both in quality 

 and position. As far as I could learn, the coal only failed 

 them here, where they had no right to expect it. 

 Course of the From the position of this coal, there can be no doubt 

 coal, and man- but 



stone bent into 

 Gothic arches. 



