XVIII. On the Parallel Roads of Glen Roy, 

 By J. Mac Culloch, M.D. F.L.S. 



PRESIDENT OF THE GEOLOGICAL SOCIETY, 



CHEMIST TO THE ORDNANCE, 



LECTURER ON CHEMISTRY AT THE ROYAL MILITARY ACADEMY, 



AND GEOLOGIST TO THE TRIGONOMETRICAL SURVEY. 



[Read 3d January, 1817.] 



JL.HE extraordinary and hitherto solitary phenomena which I 

 have undertaken to describe, although long known and celebrated 

 by the natives as the traditional works of their great ancestors, re- 

 mained concealed from the world in general till Mr. Pennant pub- 

 lished a short account of Glen Roy in an appendix to his Tour. 

 A second description appeared in the Statistical Survey of Scotland, 

 since which I know not that any attempt has been made to explain 

 the origin of the Parallel Roads, although they have long been 

 objects of curiosity to philosophical as well as to ordinary tourists. 

 However convinced the Highlanders may have formerly been that 

 these parallel roads, as they are called, were the works of Fingal 

 and the heroes of his age, they have lately inclined to a different 

 belief, and with most philosophers are willing to think that they 

 may have been the result of the action of water. Still the matter 

 remains disputed among the pardzans of the different theories, and 

 as the establishment of the latter opinion is attended with geological 

 consequences of the first importance, it deserves to be investigated 

 with the greatest care. 



