28 A Visit to Glen Clova : Its Geology and Ferns. 



as it was originally spelt, are situated upon a small eminence in 

 the marsh formerly an island in the loch. 



The greater part of the walls of the church are almost 

 entire, including the tower, which is surmounted by an octa- 

 gonal spire. They have lately been repaired by the proprietor. 

 The south-east and west walls of the cloisters are in a ruinous 

 condition. The whole building appears to have been in the 

 first pointed style of architecture, or that which prevailed in 

 Scotland during the thirteenth century. It is believed to have 

 been erected on the site of the old church of Rostinoth, 

 founded by St. Boniface when he came into Scotland in the 

 beginning of the seventh century. Growing in these marshes, 

 near to Clock sbriggs station, we found the Marsh fern, Lastrea 

 thelypteris. 



We walked round Loch Feithie on our return to Forfar, 

 a charming little lake entirely surrounded by woods, about half a 

 mile to the south of Restennet ; but it is much choked up by the 

 soldier- weed. This loch contains no deposits of marl, "which/* 

 says Sir Charles Lyell, "is owing to there being no springs in it." 

 It is only where a stream enters a lake, or where it is fed by 

 springs, which may introduce a fresh supply of calcareous matter, 

 that shells accumulate and help to form marl. For otherwise, 

 the thin shells of one generation of mollusks in decomposing 

 only afford sufficient nutriment to the succeeding races. 



On Saturday we walked to the vitrified forts, situated a little 

 to the west of the village of Aberlemno, on the north brow of 

 the Finhaven hills, and five miles N. E. from Forfar. These 

 hills form the southern boundary of the vale of Strathmore, 

 above which thev rise to the height of 600 feet, and so the fort 

 occupies a most commanding situation. The origin of these 

 vitrified forts, of which there are several in the country, though 

 this one is the most extensive, goes so far back into antiquity, 

 that not only the names, but even the races of their builders 

 are unknown. The Finhaven fort is in shape a parallelogram, 

 having its corners rounded off. It declines with the hill to the 

 W., in length from E. to W., 476 feet, at the E. end its breadth 

 is 83 feet, and at the W. 125 feet ; the wall is from three to ten 

 feet in height, but is supposed at one time to have been much 

 higher. Great quantities of the stone have been carted away 

 for mending the roads. In the west end of the fort there was a 

 well, but this is now filled up. The fort is built of several 

 kinds of stone, chiefly sandstone and gneiss, which have been 

 fused together by the action of fire, a good substitute for 

 cement. It must have required an immense amount of 

 wood to vitrify such a large fort, but in those days that could 

 easily have been obtained, for the whole of this district was 

 once covered by forest, as is shown by the quantities of old 



