322 A, Tylor on the Amiens Gravel. 
the Chemin de Fer du Nord, the height is 96 feet, (Mr. Prest- 
wich has marked this same level as 76, in his drawing, plate 
10. Phil, Trans. 1860,)* This is just 13 feet below the real 
height. Again, in Mr. Prestwich’s section, page 257, Phil 
Trans. 1864, the height of the rails at Montiers is marked 130 
says, “‘ The upper section at Montiers, which I discovered in 
1861, was conclusive as to the relative ages of the gravel 
(p. 248, Phil. Trans. 1864. — 
urements of M. Guillom, present examiners have a great _ 
vantage over their predecessors, in examining the structure 
I cannot suppose that Mr. Prestwich would now separate the 
Montiers gravels, seen in and above the railway-cutting # 
M & 9 1 y J into two 
tween the height of the gravel on the top of the r 
ailway-cur 
ting and that in the Imperial road. As nearly the whale 
the present time, with the additional information we P® Mr 
he section on Plate IV. therefore appears to d jivisiol ; 
Prestwich’s argument, on which he has constructed a 
of the gravels at St.-Acheul and at Montiers into upp tasted : 
gravels and lower valley-gravels, of different ages, 
on different horizons, separated, as he supposed, by vel belts : 
feet fod 
bare chalk from each tae upper valley-gr@ 
* This is calculated from the mean tide at St. Valery, which differs 
that at Havre. 
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