3H 



NATURE 



\_Aug. 19, 1875 



flow could still take place in a northerly direction also from 

 Lake Aral. Some sixteenth century maps show the river 

 Obi flowing out of the lake of Kitay, which is one of the 

 names of Aral ; and by such an overflow may be explained 

 that supposed irruption of Ocean into Asia which the 

 most ancient Greek and Latin authorities have recorded. 

 Nor would the demonstration of the possibility of this 

 overflow in any way affect the reputation either of Hero- 

 dotus or of Aristotle, who both maintained the isolation of 

 the Hyrcanian from the ocean ; for the overflow from Aral 

 might or might not have taken place during a series of 

 years, depending as it did upon the magnitudes of the 

 annual floods of the rivers which supplied it, at the epoch 

 when the winter broke up, on the highlands of Central 

 Asia. 



It was estimated in the note on the Hyrcanian Sea that 

 when the Oxus discharged directly westwards, the water- 

 'spread of Lake Aral and the lands drowned by its over- 

 flow might have added about 70,000 square miles to the 

 nrea of 140,000 square miles, which is possessed by the 

 Caspian of to-day. If 30,000 square miles be added 

 1 csides, for the volume which Oxus, Ochus, and Arius 

 probably supplied, the total area of the Hyrcanian Sea 

 would liave been about 250,000 square miles, which would 

 have formed a waterspread almost reaching up to the 



ridge which divides the Caspian from the Black Sea, i.e. 

 the level of the largest possible Hyrcanian Sea may have 

 been 89 feet above mean sea-level, in the lowest of the 

 two basins which formed it. The observations of Pallas 

 have, however, placed beyond doubt that the ancient 

 limits of the Caspian were situated at a much higher level 

 than this ; and since these limits, which are delineated in 

 a map illustrating his works, did not owe their existence 

 to the overflow from Aral, in conjunction with the volumes 

 of water delivered by the rivers of the Caspian basin, 

 they must have been formed by water flowing out of the 

 Euxine basin. And this latter could not consequently 

 have had at such a time a communication with the 

 Mediterranean Sea. 



We know that at the present day a very much larger 

 volume than is required to compensate its surface evapo- 

 tion is contributed by the various rivers supplying the 

 Black Sea, and passes thence through the Bosphorus into 

 the Sea of Marmora. Before this escape existeo-, the level 

 of the Euxine would have been higher, and the surplus 

 waters would have overflowed to the east by the channel 

 of the Manytsch into the basin of the Caspian, whose 

 level would, in turn, have been raised. The united water- 

 spread of the two basins would have continued to rise, 

 until the surface evaporation equalled the supply of water 



Gi'eat Ft'eshmiter MerlUerrtijtetin.B. C. I:, 



MEAN S£A IFVFL% JSua^.ne. . 



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CaxpianiSTl'. 



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it received ; or until it found an escape into a lower level, 

 and this latter circumstance was the one which almost 

 certainly occurred, and in a northern direction. 



The part of the ancient shore of the Caspian, which 

 Pallas has delineated, and which is situated at a point 

 called Cholon Komyr, in latitude 45"" 30' 25", and longitude 

 (east from Greenwich) 44° 51' 34", has a height of 221 feet 

 above the sea {b). In other words, the great inland sea of 

 fresh water, which extended from the western shores of 

 the Black Sea to the eastern shore of Lake Aral, had its 

 surface precisely on the level at which, it has been stated, 

 there is a strong presumption that Lake Aral could over- 

 flow to the north and form a junction with the Frozen 

 Ocean by the drainage lines of the Tobol and of the Obi. 

 Under all the circumstances it is scarcely hazardous to 

 say that this presumption becomes all but a certainty ; 

 and that the height of the low ridge, which divides the 

 drainage on the north of Lake Aral, will eventually be 

 found to be 220 feet or less, at its lowest point, above 

 sea-level. 



The actual original separation of the Aral and the 

 Caspian may thus be referred to the rupture of the Bos- 

 phorus, and to that consequent rush of waters from the 

 Euxine into the Mediterranean, which is known as the 

 Deluge of Deucalion. The immediate result of this cata- 

 clysm would have been a fall in the level of the Caspian 

 from 220 to 89 feet above the sea ; and though actually 

 isolated from Lake Aral, it would have appeared connected 

 will it by marshes, alimented by the overflow of the latter 



(/') See note {n). 



basin. Though the Caspian level still continued to fall, 

 from surface evaporation, the aqueous character of the 

 intervening bed of the drained-oif waters would thus have 

 been preserved for a long time, and such a condition 

 will explain the probable difference in physical aspect 

 which would distinguish the long since desiccated Aralo- 

 Caspian region if it were subjected once more to an 

 overflow of Lake Aral. The cessation of this overflow 

 would have, in the first instance, hastened the drying up 

 of the higher levels of the intervening country, and accen- 

 tuated to the Orientals upon the shores of the higher sea 

 that isolation of the two basins which the Europeans 

 upon those of the lower were not, and in fact could not 

 be, acquainted with until very long afterwards. 



Herbert Wood 



G UN- CO TTON WA TER-S HELLS 



TN the published accounts of Field Artillery Experi- 

 *- ments which are just now being carried on at Oke- 

 hampton, in Devonshire, considerable prominence has 

 been given to the formidable nature of the so-called water 

 shells,with which practice has been carried on against rows 

 of targets, in the form of " dummy " soldiers, representing 

 columns of infantry, shrapnel shells and common shells, 

 filled with gunpowder, having been fired in comparisoii 

 with them. 



The term wafer-shell denoits not a shell of special form 

 or construction, but simply a new system of bursting 



