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
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
In most branches, however, their handicraft does not appear to have risen above the ordinary level; the manufacture of linen and woollen stuffs, that subsequently flourished in central and northern Gaul, was demonstrably called into existence only by the Romans. The elaboration of metals forms an exception, and so far as we know the only one.
The copper implements not unfrequently of excellent workmanship and even now malleable, which are brought to light in the tombs of Gaul, and the carefully adjusted Arvernian gold coins, are still at the present day striking witnesses of the skill of the Celtic workers in copper and gold; and with this the reports of the ancients well accord, that the Romans learned the art of tinning from the Bituriges and that of silvering from the Alesini--inventions, the first of which was naturally suggested by the traffic' in tin, and both of which were probably made in the period of Celtic freedom.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/5-07-subjugation-west.asp?pg=23