1 82 NATURAL SCIENCE. March, 



the great depths must be very old or permanent ; so let us compare 

 the character of the sediments near the existing coasts. 



The Old Red Sandstone is an extra-marine formation ; yet the 

 Old Red Sandstone runs out into the sea in the Orkneys, reappears 

 in the Shetlands, and the same palaeontological and extra-marine 

 character is known in Spitzbergen. Old [Red exists on the north 

 coast of Lapland, and on the White Sea. The plant-bearing beds 

 of the Karoo run out to sea in British Kaffraria ; they are repeated 

 in India and Australia. The fresh- water beds of the Wealden pass 

 over from England to the Continent ; they not only reappear in 

 Hanover, they run out into the Atlantic in the lower Charente, and on 

 the coasts of Spain and Portugal. Why must the continent which 

 formerly bounded all these vast fresh-water basins have been limited 

 within the existing i,ooo- or 1,500- or 2,000- fathom line? The 

 breaking down of the bed of the ^Egean Sea, described by Spratt 

 and Neumayr, is of Post-phocene date, for Pliocene fresh-water 

 deposits form parts of the coast ; and yet the depths go far beyond 

 1,000 fathoms. In 1892 the "Pola" measured 3,591 metres in 

 lat. 35° 52 36", long. 29° i' 24" E., quite near the south-west coast 

 of Asia Minor, and close to the mighty Ak Dagh (r 0,000 feet); and 

 this although the separation of the neighbouring island of Rhodes 

 is so recent, that not only do the Pliocene fresh-water beds pass over 

 from the Continent, but according to Bukowski also considerable 

 masses of Middle Pliocene fluviatile conglomerates, originating in Asia 

 Minor, have been deposited by a great river on this island. 



Now suppose the existing quantity of oceanic water to decrease, 

 say by evaporation into the ether, as Zollner once thought, or in 

 any other way ; we might by this gradual diminution of the entire 

 quantity attain a beach-line 500 fathoms below the present shores. 

 The continents would appear so much higher, and dry land would 

 extend. Plains would successively appear, more or less similar to 

 Holland, and our present rivers Shannon, Seine, Loire, Sec, would 

 flow through these plains. In most cases the rivers would be caused 

 to cut back their valleys, new transverse and parallel lines of erosion 

 would appear, and the plain would be diversified into hills and valleys. 

 The hills south of the Shannon would i5robably show the rest of those 

 anticlines and synclines which dip below the ocean in south-west 

 Ireland, and we should be able to see a greater part of the northern 

 Armorican arch. The Scilly Islands would appear as another 

 granitic laccolite within the continued Armorican region of Cornwall. 

 The gneiss of Eddystone would come up within this northern Armori- 

 can arch, exactly as the gneisses of the Alps stand up within and 

 behind the folded arches. In a similar way, in the south, the anti- 

 clines and synclines of French Armorica, which disappear north and 

 south of Brest, would begin to be visible ; but in the north-west of 

 Ireland we should see a plateau, ending in a steep cliff, the abrupt 

 boundary of a deep channel, separating the great island of Rockall 



