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XL VII. 



ON SOME SPECIMENS FKOM WADY HALFA, UPPEK EGYPT. 

 By J. SHEAESON HYLAND, Ph. D., M.A., of the Geological 

 Survey of Ireland. 



[Eead February 10, 1890.] 



During the recent Soudan Campaign Wady Haifa was occupied 

 by the English Expeditionary Force, and became one of their 

 principal stations on the Nile — a large hospital being established 

 there. Surgeon-Major S. Archer, of the Army Medical Depart- 

 ment, seized the opportunity afforded him in his leisure hours of 

 searching the immediate vicinity for remains of the stone age. 

 He was successful in discovering an immense number of flakes 

 and hammerstones ; but more finished implements appeared to be 

 scarce, and only a few were found. 



Whilst in England in 1888, I had occasion to examine the 

 collection, which is now in the possession of Mr. F. Archer of 

 Liverpool, and was particularly struck by the igneous aspect 

 presented by the material composing some of the more rudely 

 fashioned flakes. As may be inferred from the long- known 

 occurrence of jaspers, &c, upon the Egyptian desert, the mass 

 of the collection consists of siliceous pebbles. I had sections cut 

 from the igneous-looking material, and was not disappointed in 

 my expectations. But, before entering upon a microscopical de- 

 scription of this rock, a short account of the other specimens may 

 be given. 



The hammerstones consist of silicified wood, masses of which 

 are found upon the surface of the country. The material is 

 hornstone-like in appearance, highly siliceous, and, accordingly, 

 very suitable for hammers. A thin section shows, under the 

 microscope, a well-defined organic structure. The wood is con- 

 verted into chalcedony, more or less discoloured by ferruginous 

 matter. Sometimes there is an alternation of chalcedony and 

 crystalline quartz ; the latter is then arranged parallel to the 



