372 Beviewfi — OeiMe^s Ancient Volcanoes of Great Britain. 



" A contrast of another type meets us in the broad midland valley 

 of Scotland. Around the city of Edinburgh, for instance, the land- 

 scape is diversified by many hills and crags, which show where 

 harder rocks project from amidst the sediments of the Carboniferous 

 system. On some of the crags the forts of the early races, the 

 towers of Celts and Saxon, and the feudal castles of the Middle 

 Ages, were successively planted, and round their base clustered for 

 protection the cots of the peasants and the earliest homesteads of 

 the future city. Beneath these crags many of the most notable 

 events in the stormy annals of the country were transacted. Under 

 their shadow, and not without inspiration from their local form and 

 colour, literature, art, and science have arisen and flourished. 

 Nowhere in short, within the compass of the British Isles, has the 

 political and intellectual progress of the people been more plainly 

 affected by the environment than in the central district of Scotland." 



" When now we inquire into the origin and history of the topography 

 which has so influenced the population around it, we find that its 

 prominences are relics of ancient volcanoes. The feudal towers are 

 based on sills and dykes and necks. The fields and gardens, 

 monuments and roadways, overlie sheets of lava or beds of volcanic 

 ashes. Not only is every conspicuous eminence immediately around 

 of volcanic origin, but even the ranges of blue hills that close in 

 the distant view to south and north and east and west are mainly 

 built up of lavas and tuffs. The eruptions of which these heights 

 are memorials belong to a vast range of geological ages, the latest 

 of them having passed away long before the advent of man. 



"But they have left their traces deeply engraved in the rocky 

 framework of the landscape. While human history, stormy or 

 peaceful, has been slowly evolving itself during the progress of the 

 centuries in these fertile lowlands, the crags and heights have 

 remained as memorials of an earlier history when Central Scotland 

 continued for many ages to be the theatre of vigorous volcanic 

 activity." (Vol. i, pp. 104, 105.) 



Jlie Pvys. — As an illustrative example of the Carboniferous puys 

 of Scotland, we give that of the junction of the amygdaloidal basalt 

 with the shales and limestone half a mile east from Kinghorn, 

 Fife. (Plate XVI.) 



" When the puys began their activity, this district was gradually 

 dotted over with little volcanic cones. At the same time it was 

 affected by the general movement of slow subsidence which 

 embraced all Central Scotland. Cone after cone, more or less effaced 

 by the waters which closed over it, was carried down and buried 

 under the growing accumulation of sediment. New vents, how- 

 ever, continued to be opened elsewhere, throwing out for a time 

 their showers of dust and stones, and then lapsing into quiescence 

 as they sank into the lagoon. Two groups of volcanoes emitted 

 streams of lava and built up long volcanic ridges — those of Fife and 

 West Lothian. 



" The occasional presence of the sea over the ai'ea is well shown 

 bv the occurrence of thin bands of limestone or shale, containing 

 such fossils as species of Orthoceras, Bellerophon, and Discina, which 



