Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
Caesar, who had reason for not altogether trusting
his staff of officers, had at the very outset sent away
all the officers' horses, so as to make the necessity of holding
their ground thoroughly clear to his troops; in fact the battle,
had the Romans lost it, would have probably brought about
the annihilation of the Roman army.
The Roman troops
were too much exhausted to pursue the conquered with vigour;
but in consequence of the proclamation of Caesar that he would
treat all who should support the Helvetii as like the Helvetii
themselves enemies of the Romans, all support was refused
to the beaten army whithersoever it went-- in the first instance,
in the canton of the Lingones (about Langres)--and, deprived
of all supplies and of their baggage and burdened by the mass
of camp-followers incapable of fighting, they were under the necessity
of submitting to the Roman general.