506 Ancient Vitrified Beacon Stations. 



term Pendentia would be even more appropriate than Tardi- 

 grade, for these mammalia. 



ANCIENT VITRIFIED BEACON STATIONS. 

 To the Editor of the Monthly American Journal of Geology. 



Sir, — Your readers, perhaps, are aware that there are in 

 Scotland certain stations of an irregularly round or elliptical 

 form, in somewhat elevated situations, surrounded by one or 

 more stone walls, or ramparts, rudely put together, and without 

 any regular masonry. These walls are constructed of fragments 

 of primary rocks, granite, gneiss, mica-slate, and other felt- 

 spathic rocks. About half a century ago, these stations attracted 

 a great deal of attention, from its being observed that the 

 greater number of them had these walls partially, or altogether 

 vitrified, or slagged together into a coherent mass, evidently 

 by the action of fire. Many theories were brought forward 

 to account for this unusual appearance. By some, the vitrifica- 

 tion of these walls was attributed to volcanic agency, and the 

 area which they surrounded was considered as a crater. Mr. 

 Pennant, the naturalist, and other eminent persons, maintained 

 this opinion. This, however, gave way to another, brought for- 

 ward by Mr. Williams, a mineral surveyor, in 1777, who sup- 

 posed them to have been ancient forts, or defences, and that the 

 vitrification of the walls had been artificially produced, by lay- 

 ing the mineral materials upon beds of fuel, and firing it. Dr. 

 Maculloch defended this theory in the Transactions of the Geo- 

 logical Society of London. In 1787, lord Woodhouselee proposed 

 a new theory, in the Transactions of the Royal Soiciety of Edin- 

 burgh. He supposed these stations to have had a superstructure 

 of wood built upon these walls, and that the vitrification was 

 produced by the destruction of the timber by fire. 



A more reasonable supposition than any of these was subse- 

 quently brought forward in that valuable work, the Statistical 

 account of Scotland, a work of which too much cannot be said 

 in praise, or of its public spirited and venerable projector. Sir 

 John Sinclair, Bart. This was the opinion, that the vitrification 

 of these walls was owing to the action of beacon fires, and that 

 these stations were not ancient forts, but beacon sites, " gene- 



