FABRI are workmen who make anything out of hard materials, as _fabri
tignarii_, carpenters, _fabri aerarii_, smiths, &c. The different
trades were divided by Numa into nine collegia, which correspond to
our companies or guilds. In the constitution of Servius Tullius, the
_fabri tignarii_ and the _fabri aerarii_ or _ferrarii_ were formed
into two centuries, which were called the centuriae _fabrum_ (not
_fabrorum_). They did not belong to any of the five classes into
which Servius divided the people; but the _fabri tign._ probably
voted with the first class, and the _fabri aer._ with the second.
The fabri in the army were under the command of an officer called
_praefectus fabrûm_.