8!^ Mr Menteath on the Geologij of Nithsdale. 



The bottom of the valley of Closeburn is covered with second- 

 ary rocks. These are sandstone and limestone. The most 

 abundant rock is sandstone. Of it there are three varieties, the 

 red, white, and grey. The red appears to be the new red sand- 

 stone, and is by far the most abundant. It varies much in its 

 texture, being sometimes bard, but oftener soft and friable. It 

 lies over all the other strata of the basin, but is almost 

 entirely confined to the east side of the Nith, as scarce- 

 ly any of it is seen on the west. One of the best examples of 

 the appearance of its varied structure, and the irregularity of its 

 dip, may be seen at the Gateley Bridge Quarry on the Cample, 

 where this red sandstone exhibits its beds lying in all manner of 

 directions, horizontal, upright, and variously inclined. In this 

 quarry roofing-flags are raised, which are carried to a great dis- 

 tance, and even exported to England. Being pervious to water, 

 they are unfit for roofing until they have been brushed over 

 with coal-tar, when they become an excellent substitute for slate. 

 Not only flags for roofs, but also lintels of doors, windows, &c. are 

 here prepared, and supply the whole neighbourhood. At Crigup 

 Linn the new red sandstone covers the other strata of the basin, 

 ' which are to be seen rising from underneath it. The red sandstone, 

 easily worn away by the running water, is at the Crigup Linn, 

 by the continual chaffing of the Crigup, scooped into a very 

 deep ravine, its sides presenting rocks of every picturesque form, 

 and overhung by rich foliage. It was to this romantic dell that 

 the unjustly persecuted Covenanters fled for shelter in their des- 

 perate fortunes. And the pen of the inimitable Sir Waiter 

 Scott has lately given this linn a classic interest, by having, in his 

 tale of Mortality, made the Crigup Linn the retreat of the da- 

 ring Balfour of Burleigh. 



The red sandstone of this valley is, in general, a good build- 

 ing stone. The most esteemed is that raised at the Gateley 

 Bridge quarry, where it is hard, tough, and very durable, re- 

 sisting, in those houses built of it, the action of the weather, 

 and indicating no appearance of waste or decay. Other but 

 less frequent varieties of this sandstone, are soft, and decay on 

 exposure to the weather. Of this a striking proof may be ad- 

 duced in the case of Drumlanrig Castle, which was built at the 

 .same time with Heriot's I^ospital, by the same architect Sir 



