212 Dana and Chambers on Ancient Sea-Margins. 



Mr Chambers' work contains extended descriptions of the 

 localities mentioned, illustrated by excellent drawings. 



Among the most remarkable of the terraced valleys of 

 Scotland are those of Glen Roy and the adjoining valleys, 

 whose terraces are called the Parallel Roads or shelves of 

 Lochaber. This region attracted the attention of MacCulloch 

 in 1817, who published an elaborate article upon them in the 

 Geological Transactions.* Since then they have been the sub- 

 ject of study by Sir Thomas Dick Lauder,t Mr C. Darwin, J 

 Buckland, Agassiz,§ Mr Kemp,|| Mr David Milne,1[ Sir 

 George S. Mackenzie,** and Mr James Thomson jun.^t 

 Speaking of these Lochaber terraces, MacCulloch says : — 



The appearance of the Parallel Roads is so extraordinary 

 as to impress the imagination of the most unphilosophical, 

 nay, even of the most incurious spectator. * * * On each 

 side of a long, hollow, deep valley, bounded by dark and lofty 

 mountains, and at a great elevation, three strong lines are 

 traced parallel to each other, and to the horizon, the levels 

 of the opposite ones coinciding precisely with each other. So 

 rarely does Nature present us in her large features with ar- 

 tificial forms, or with the semblance of mathematical exact- 

 ness, that no conviction of the contrary can divest the specta- 

 tor of the feeling that he is contemplating a work of art, a 

 work of which the gigantic dimensions and bold features ap- 

 pear to surpass the efforts of mortal power. 



Several views of the region are given by MacCulloch, and 

 Chambers observed three lines extend for five or six miles 



♦ Trans. Geol. Soc. London, vol. iv., 1817, p. 314. 



t Trans. Royal Society of Edinburgh, 1818, vol. ix., p. 1. 



I Trans. Royal Society, London, 1839, p. 39. 

 § Jameson's Edin. New Phil. Jour., 1842. 



II A writer in the Athenaeum, of September 23, claims, for Mr Kemp of Ga- 

 lashiels, his having first investigated the inland terraces of Scotland, and states 

 that his views, which are the same as are presented by Mr Chambers, were no- 

 ticed in Chambers' Journal as early as 1840. 



% Jameson's Edin. New Phil. Jour., vol. xliii., p. 339, 1847. 



** Ibid., vol. xliv., p. 1, with a map, Jan. 1848. A previous memoir by Mac- 

 kenzie was read on the subject before the Royal Society of Edinburgh in 1842, 

 and a still earlier publication appeared in Brewster's Phil. Journal for 1833. 



tt Ibid., vol. xlv., p. 49, 1848. 



