264 TRANSLATIONS AND SELECTED ARTICLES, 
the stratum of the age of bronze showed itself in the northern side, 
very distinctly and regularly, for a length of 200 feet. 
After all which precedes, we can see that it would be difficult to 
imagine a greater regularity in the entirety as well as in the details 
of the phenomena, and this circumstance renders perfectly legitimate 
the application of our calculus. So then, taking our departure from the 
observations and measurements made on and in the decline of the south- 
ern side of the cone, keeping account of the effects of the embankments, 
but augmenting their age to double; that is to say, giving them a date 
of three centuries, taking notice of the thickness of the vegetable earth 
on the present surface, considering that the volume of the cone in- 
creases as the cube of its radius, and that the depths of its different 
strata are thus not exactly in direct ratio with their age, and giving 
finally to the Roman layer an antiquity of at least thirteen centuries, 
or at most eighteen, although nineteen centuries have passed since the 
Romans invaded this country, we find for the layer of the age of bronze 
an antiquity of at least twenty-nine centuries or forty-two at most ; 
for the layer of the age of stone an antiquity of at least forty-seven 
centuries or at most seventy ; and for the whole of the cone a total 
age of seventy-four or at most 110 centuries. The author believes 
that we would approach near enough to the truth, by deducting only 
two centuries for the action of the dykes, and attributing to the 
Roman deposit an antiquity of sixteen centuries; that is to say, in 
bringing it to the third century of the Christian era. This would give 
to the layer of the age of bronze an antiquity of thirty-eight centuries, 
twenty centuries before Jesus Christ; and for the age of stone an 
antiquity of sixty-four centuries. But in order not to risk being too 
precise in counting the centuries, we will stop at the assertion, that 
the layer in question of the age of bronze has a date of from 3000 to 
4000 years, and that of the age of stone from 5000 to 7000 years. 
It is evident that each of our ancient soils would not represent 
the total length of each of the corresponding ages, but only some 
portion of each of these ages, the small period more or less long, 
during which the torrent has worked in the central region of its 
cone, without spreading itself on its sides, where vegetation could 
then have taken place. The surface of the cone, for the greater 
part of the time, must only have presented the appearance of a heap 
of stones, on which a few bushes grew. Thus we have not remarked 
traces of human occupation in the gravel intercalated between the 
