History of Julius Caesar Vol. 2 of 2. Napoleon III
plain slightly inclined towards the river. It is marked by a green tint on Plate 3. People can descend from all sides and approach the Rhone, the bank of which is flat. Opposite, the left bank presents insurmountable obstacles until below Cologny, at
The Helvetii, established on the heights of Pougny and Colonges, could descend to the Rhone, and cross it between Etournel and the hamlet of Les Isles. The Romans had thus to unite the escarpments which terminate at Cologny with the impracticable slopes of the mountain of Le Vuache. Here again we shall see that they took advantage of the peculiarities of the ground.
At the village of Cologny, the heights form a triangular plateau,
To sum up: the works executed on five principal points, between Geneva and the Jura, represent a total length of about 5,000 mètres, that is, less than the sixth part of the development of the course of the Rhone.
Admitting that Cæsar had at his disposal 10,000 men, we may suppose that he distributed them in the following manner: – 3,000 men on the heights of Avully, his head-quarters; 2,500 at Geneva; 1,000 on the plateau of Aire-la-Ville; 2,000 at Chancy; and 1,500 on the plateau of Cologny. These 10,000 men might be concentrated: in two hours, on the heights between Aire-la-Ville and Cartigny; in three hours, on the heights of Avully; in three hours and a half, on the plateau of Chancy; in three hours and a half, these troops, with the exception of those encamped at Geneva, might be brought together between Cologny and the fort of L’Ecluse. It would require five hours to carry the detachment from Geneva thither.
The detachments mentioned above, with the exception of that of Geneva, were established in what Cæsar calls the
Cæsar could reconnoitre every instant the march and designs of the Helvetii, the heights of the left bank of the Rhone presenting a great number of positions where it was easy to place advantageously posts of observation. Commandant Stoffel has pointed out six, which are marked on Plate 3. As it will be observed, the Helvetii, in crossing the Rhone, could not be disturbed by darts thrown from the top of the retrenchments, for these darts would not carry to the left bank of the river. Now there exists at present, between this bank and the foot of the heights in which these trenches were cut, flat ground of more or less extent. Admitting, then, that the Rhone flowed nineteen centuries ago in the same bed as at the present day, we may ask if the Romans did not construct, in these low parts near the bank, ordinary retrenchments, composed of a fosse and rampart. The excavations undertaken by the Commandant Stoffel have revealed everywhere, in these plains, the existence of ground formed by alluvium, which would lead us to believe that the Rhone once covered them. However, even if at that epoch these little plains had been already uncovered, either wholly or in part, we can hardly suppose that Cæsar would have raised works there, since the heights situated in the rear permitted him, with less labour, to create a more redoubtable defence – that of the trenches opened along the crests. As we see, the obstacle presented to the assailants began only with these trenches, at the top of the slopes.
As to the vestiges which still appear to exist, they may be described as follows. The slopes which the Romans fortified at Chancy, from
We must further mention the projection of land
It is easy to estimate approximately the time which it would have taken Cæsar’s troops to construct the 5,000 mètres of trenches which extended, at separate intervals, from Geneva to the Jura.
Let us consider, to fix our ideas, a ground A D V, inclined at 45 degrees, in which is to be made the trench A B C D. The great wall A B C had 16 Roman feet in elevation: we will suppose that A B was inclined at 5 on 1, and that the small wall D C was 6 feet high.
The amount of rubbish removed would be as follows: – Section A B C D = 64 square feet, or, reducing it into square mètres, A B C D = 5 square mètres 60 centimètres.
The mètre in length of the earth thrown out would give thus 5·60 cubic mètres.
If we consider the facility of labour in the trench, since the earth has only to be thrown down the slope, we shall see that two men can dig three mètres in length of this trench in two days. Therefore, admitting that the 10,000 men at Cæsar’s disposal had only been employed a quarter of the time, from two to three days would have been sufficient for the execution of the complete work.
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It has been considered to have been an error of Cæsar to place the Santones in the proximity of the Tolosates: modern researchers have proved that the two peoples were not more than thirty or forty leagues from each other.
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Several authors have stated wrongly that Cæsar went into Illyria; he informs us himself (
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We believe, with General de Gœler, from the itinerary marked on the Peutingerian table, that the troops of Cæsar passed by Altinum (
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“Locis superioribus occupatis.” (
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There is difference of opinion as to the site of Ocelum. The following remark has been communicated to me by M.E. Celesia, who is preparing