14 



THE GEOLOGIST. 



land in the vicinity of these islands even during the last century. 

 Another fact, which came to my knowledge while sojourning in the 

 isles, confirms me in this opinion. The masons who had been engaged 

 in laying the foundations of a large warehouse, belonging to Mr. Ed- 

 wards, a short distance from the strand in the Pool of St. Mary's, 

 assured me that when they had dug down several feet below the sur- 

 face, they came across the remains of former wooden buildings which, 

 at one time, must have been above the level of the sea, although they 

 were thus found considerably below it. 



Possibly, at no very remote period, geologically speaking, the whole 

 of this group to the north, including Bryer, Tresco, St. Martin's, and 

 the adjoining islets, have formed one continuous island, the soundings 

 between the contiguous portions being still very shallow, so much so 

 that several of them can be reached from the others by walking over 

 the bars at low water. The question of their continuity at any former 

 time with the mainland is one of greater difficulty j for although the 

 tradition previously referred to speaks of a large tract of country 

 covered with parish churches, and called the " Leonais," as formerly 

 uniting Scilly with Cornwall — and there are not wanting stories also 

 of the remains of windows and doorways having been seen midway 

 beneath the ocean in seasons of clear weather — yet no facts of a 

 geologic character, in any way bearing out this view, have as yet been 

 ascertained. I made the most careful search, during my stay in the 

 islands, to discover, if it were possible, any traces of greenstone or 

 clayslate in those parts of the islands looking towards the Cornwall 

 shores, but I could discover nothing of the kind. On the summit of 

 the promontory called the Hugh, forming a part of St. Mary's, I did 

 indeed find clayslate ; and on the very highest point of Newford Down, 

 in a pit not far from the Telegraph Station, I met with similar traces; 

 but both of these points would be out of the line of communication with 

 the nearest points of the Cornish coast, and they are only interesting 

 inasmuch as they prove that some land, higher than any now existing 

 in St. Mary's, has formerly consisted of metamorphic rocks, the 

 broken fragments of which, after having been subjected to the action 

 of water, have been deposited in an irregularly stratified manner 

 amidst the shattered debris of the surrounding granitic rocks. The 

 position in which I found these solitary traces of slate-rock was in a 



