Cambridge Philosophical Society. 229 



ance for the foundation of the platform having been below the then 

 surface. It is assumed that the platform was laid in the middle of 

 the reign of that king, that is, in the year 1361 b.c, which, added 

 to A.D. 1854, when the observation was made, give 3215 years during 

 which the above depth of sediment was accumulated ; and supposing 

 that no disturbing cause had interfered with the normal rate of 

 deposition in this locality, and of which there is no evidence, we 

 have thus a mean rate of increase within a small fraction of ^\ inches 

 in a century. Below the platform, there were 32 feet of the total 

 depth penetrated, but the lowest two feet consisted of sand, below 

 which it is possible there may be no true Nile sediment in this loca- 

 lity, thus leaving 30 feet of the latter. If that amount has been de- 

 posited at the same rate of 3|^ inches in a century, it gives for the 

 lowest part deposited an age of 10,285 years before the middle of 

 the reign of Ramesses II., 1 1,646 years B.C., and 13,500 years before 

 A.D. 1854. 



The author then observes, that these recent researches, taken in 

 conjunction with those of a similar kind by the French engineers 

 at the close of the last century, high in Upper Egypt, afford strong 

 presumptive evidence that the whole of the land of Egypt between 

 the bounding hills, from the first cataract to the sea, extending 

 nearly 700 miles — that land which is associated in our minds with all 

 that is most ancient in history or tradition — belongs entirely to the 

 recent geological period. No trace of an extinct organism has been 

 turned up to take the formation of the alluvial land of Egypt beyond 

 that modern epoch from which we are used to carry back our geo- 

 logical reckonings. 



The author concludes with some remarks on the evidence which 

 these researches seem to afford of a very early existence of man in 

 Egypt. In a large majority of the excavations and borings the 

 sediment was found to contain at various depths, and frequently at 

 the lowest, small fragments of burnt brick and of j^ottery. In the 

 lowest part of the boring of the sediment at the colossal statue in 

 Memphi?, at a depth of 39 feet from the surface of the ground, con- 

 sbting throughout of true Nile sediment, the instrument brought 

 up a fragment of pottery. [This fragment was exhibited when the 

 paper was read.] Having been found at a depth of 39 feet, it 

 ^^ould seem to be a true record of the existence of man 13,371 years 

 before A.D. 1854, reckoning by the before-mentioned rate of increase 

 of 3| nches in a century; 11,517 years before the Christian era; 

 and 7625 years before the beginning assigned by Lepsius to the 

 reign of Mencs, the founder of Memphis ; of man, moreover, in a 

 stale of civilization, so far, at least, as to be able to fashion clay into 

 vessels, and to know how to harden them by the action of a strong 

 heat 



CAMBRIDGE PHILOSOPHICAL SOCIETY. 

 [Continued from p. 158.] 

 Nov. 23. 1857. — A paper was read by Professor Thompson, " On 

 the Sophista of Plato." 

 In this paper the genuinenees of the Sophisla was defended, and 



