70 REPORT — 1865. 



volcanos. 3. Ejections of steam from earthquakes. 4. Ejections of steam from 

 geysers. 5. Rocks ejected from a volcano by steam. 6. Active volcanos below 

 the sea necessarily produce steam and earthquakes. 7. Ejections of water and of 

 mud (which implies the presence of water) from volcanos ; also sinkings of rivers 

 and other waters. 8. Ejections of water, often hot, from earthquakes; from risings 

 and sinkings of strata ; and from earthquakes combined with volcanos. 9. Earth- 

 quakes fed by water. 10. Active volcanos fed by water. 11. Volcanos, earth- 

 quakes, hot water, and increasing temperature of hot springs ; sometimes all con- 

 nected together. 12. Deposits of water, and of ice and snow, ready to descend into 

 volcanos by gravitation. The evidences appear in detail in the ' Artisan ' of Janu- 

 ary, Eebruary, and March 1866. 



On Extensive and Deep Shillings of Lands in the Channel Islands Seas, and 



on some Changes of the French Coast of the Bay of Biscay within the. 



Historical Period. By E. A. Peacock, Jersey. 



It is well known that quantities of trees with roots attached, and other supra- 

 marine products, have been found all along the west coast of Normandy, along the 

 eastern half of the north coast of Britanny, in the Bay of Mont S. Michel, on the 

 west, south, and north-east of Jersey, and on the east and west of Guernsey, be- 

 tween high and low water, and even lower than the latter. Not only so. but in 1787 

 thousands of trunks (with roots) of trees were washed up on the west of Jersey from 

 Rigdon shoal and Great Bank, which are respectively at 2 and 3 miles westward of 

 high water, and on the latter of which banks the soundings are from 7 to 9 fathoms 

 at low water, and the greatest rise of tide 42 feet. And supposing the original height 

 of the ground 10 feet above high water, it follows there must have been a sinking 

 of at least a hundred feet. Prodigious quantities of trees also came up from the 

 bay of Mont S. Michel after a hurricane on the 9th of January, 1735, and its sands 

 have been penetrated more than 50 feet in several places without reaching their 

 bottom, though it is well known that previous to a.d. 709 the whole bay, as far as 

 Chausey rocks, and for a considerable breadth northwards as far as Cape la Hague, 

 and the country southwards as far as Dol, was the forest of Sciscy. The positions 

 of four ancient monasteries and the Bourg of Lhan-Kafruth, which stood in this 

 forest, are known. One of these stood where there is now a sounding of 54 feet at 

 low water, and the greatest rise of tide is also 54 feet, to which add 10 feet for sup- 

 posed height of the monastery above high water, and we have a total of 118 feet of 

 sinking. If the late Abbe Manet's figures are to be relied on, the Mont was once 

 176 English feet higher than it is now. It is certain, from the nearly contemporary re- 

 cords contained in 'Acta Sanctorum,' Dom Bouquet's 'Historians of France,' 'Neus- 

 tria Pia,' and other middle-age authorities, that Mont S. Michel, which contains 

 now only about 20 acres, was immediately previous to a.d. 709, 6 miles long by 4 

 miles broad and covered by forests ; and that the rock was once a Mountain, and 

 6 miles, or, according to other accounts, 8 miles from the ocean, and even much 

 more. A large tract of land 20 miles long, and in some places 2^ miles broad, now 

 lost, extended from Cancalle Point, past S. Malo to Cape Frehel. There have been 

 about nine different sinkings. 



The remarkable angularity of the vast tracts of marine rocks on the south and 

 west of Jersey, though daily subject to the action of the tides, can only be accounted 

 for, he thought, by their having only been exposed to that action since 1356, at 

 which date the tracts sunk, and the soil upon them was washed away, and the 

 angles of the rocks have not yet had time to become rounded. Poingdestre, 

 a learned antiquary born in Jersey in 1609, substantially confirms some of these 

 views in No. 5417 of the Harleian MSS., which is known to be of the date 1685. 

 The Ecrehous and Dirouilles on the north-east of Jersey are known to have been 

 much more extensive than at present ; they also sunk, probably in 1356. Ptolemy 

 gives latitudes and longitudes in his own way, and some of them having been re- 

 duced to modern latitudes and longitudes, give important corroborative results. 

 For example, taking his Ocrinum promontory (the Lizard), and his centre of the 

 Isle of Vectis (Wight) as points of departure, his Gobseum promontory of the 

 ( Vrismii becomes 4° 51'-21 W. long, and 48°33'T8 lat., which nearly coincide with 

 the present north-western angle of Britanny, and therefore prove that in this instance 



