W. A. E. Ussher — Historical Geology of Cornwall. 33 



" If the Lyonesse country really existed in Ptolemy's time 

 (a.d. 117 to 161), it cannot have extended as far westwards as is 

 shown on the map in the Churchman's Magazine (for July, 1863, 

 p. 39), from Land's End and Lizard Point to and comprising the 

 Scilly Isles. Because Strabo, who flourished at least a century 

 before Ptolemy, quoting Posidonius, who was still older, mentions 

 those islands as then existing under the name of Cassiterides (book iii. 

 cap. ii. § 9), and that they were ten in number (Ibid. cap. v. § 11)." 



" Dr. Paris, in his ' Guide to Mounts Bay and the Land's End,' 

 p. 91, mentions Camden's tradition of the Lyonesse (the Silurian 

 Lyonois), said to have contained 140 parish churches, all of which 

 were swept away by the ocean." He says further that the Scilly 

 Isles are now 140 in number, though only six are inhabited. 



Camden (Britannia, edit. 1722) says, " The Scilly Isles are called 

 by Antoninus, Sigdeles ; by Sulpitius Severus (died a.d. 420), 

 Sillinag; by Solinus, Silures; by Dionysius Alexandrinus, Hesperides; 

 by Festus Avienus (latter part of fourth century), Ostrymnides ; by 

 several Greek writers, including Diodorus, and by Pliny the Elder, 

 Cassiterides." 1 



Dr. Borlase, 2 in a letter to the Eev. J. Birch on the Scilly Isles, says 

 that the present inhabitants are new comers, having no connexion 

 with the old race, as all the antiquities found in the islands belong 

 to the rudest Druidic times. 



In isles now uninhabited and not used for pasturage, rude stone 

 pillars, erect circles of stone, kistvaens, innumerable rock basins, 

 and tolmens. 3 are found, whilst the small islands, tenements, and 

 creeks, are called by British names. 



Within the three years previous to 1753, he states that the ad- 

 vance of the sea in the Scilly Isles has been very considerable ; this 

 advance being, in his opinion, due to subsidence for the following 

 reasons : Strabo's opinion as to their number (vide supra) and as to 

 one only being desert and uninhabited ; the fact that the Isle of 

 Scilly, which gives its name to the group, is now a high barren 

 rock, a furlong across, with cliffs to which only sea-birds can obtain 

 access. 



The flats which stretch from one island to another are plain 

 evidences of a former union between many now distinct islands. 

 The flats between the islands of Trescan, Brehar, and Sampson, are 

 left quite dry at a spring-tide low-water, when walls and ruins have 

 frequently been seen through the shifting sands, covered by 10 to 20 

 feet of water at high tide. As these foundations were probably at 

 one time six feet at least above high-water mark, the advance of the 

 sea by denuding action alone would be insufficient to account for 

 their present position, "ten feet below high- water." Whence he 

 considers that " a subsidence amounting to 16 feet at least has taken 



1 Peacock, p. 109. 



3 Phil. Trans, for 1753, vol. 48, p. 326. 



3 Tolmens. — Oval or spheroidal rocks, when resting on two others, with a cavity 

 between, are called by Dr. Borlase tolmens (stones with holes), and are supposed by 

 him to have been rock deities (Came on the Scilly Isles). — T.E G.S. Corn. vol. vii. 

 p. 144. 



DECADE II. — VOL. VI. — NO. I. 3 



