the Land at the Head of the Persian Gulf, 43 



say, at six times more than the area of the countries drained 

 by the rivers of the Adriatic. 



If, then, in two thousand years a tract of 1000 square miles 

 has been formed in the Gulf of Adria from the alluvium 

 brought down by the rivers from 45,000 square miles of ter- 

 ritory, it will (ceteris paribus) result, that at the head of the 

 Persian Gulf the accession from 270,000 square miles of 

 country will have been six times greater in amount; that is to 

 say, a formation of not less than 6000 square miles of alluvial 

 soil will have taken place within the last two thousand years : 

 and if we compute the same rate of increase to have existed 

 back from the building of Babel, this formation will have ex- 

 tended to 13,800 square miles of land. 



In making the foregoing calculation it has been assumed 

 that the circumstances are similar in both cases : this, how- 

 ever, is not precisely the case. The Adriatic is a gulf in a 

 tideless (or almost tideless) sea : the rise and fall of the tide at 

 the head of the Persian Gulf is (I believe,) as much as 8 or 9 

 feet at spring tides. From the effect, therefore, of the tide, 

 and also from that of a current which sets across the head of 

 the Persian Gulf from east to west, the accumulation at the 

 mouths of the rivers would doubtless be checked, and a por- 

 tion of the alluvium would be carried eastward and south- 

 ward, and be dispersed in those directions over the bottom 

 of the gulf. That such is actually the case is shown by the 

 chart of this gulf lately constructed by the officers employed 

 in its survey by the East India Company ; from which it ap- 

 pears, that whilst along the north-eastern or Persian side of 

 the gulf the depth, in great part, exceeds forty fathoms, along 

 the whole of the Arabian or western and southern side it varies 

 from twenty fathoms to shallows which are unnavigable, and 

 which, to all appearance, will soon rise altogether above the 

 level of the sea. 



But, on the other hand, the much greater depth of the 

 Adriatic, and of the Mediterranean generally, (which in many 

 parts close to the shore is 2000 feet, and near Gibraltar even 

 as much as 6000 feet deep*,) would tend very materially to 

 reduce the rate of the superficial growth of the alluvial soil in 

 that sea ; and would thus — to a considerable extent, at least, — 

 counterbalance the effects of the tide and current in the Per- 

 sian Gulf. 



On the whole, therefore, when we take into consideration 

 the immense quantity of alluvial matter which is carried down 

 into the Persian Gulf, we cannot hesitate to admit that Pliny 



* Principles of Geology, vol. i. p. 237 J first edition. 

 G2 



