SESTERTĬUS, a Roman coin, which properly belonged to the silver
coinage, in which it was one-fourth of the denarius, and therefore
equal to 2½ asses. Hence the name, which is an abbreviation of
_semis tertius_ (sc. _nummus_), the Roman mode of expressing 2½.
The word _nummus_ is often expressed with _sestertius_, and often
it stands alone, meaning _sestertius_. Hence the symbol HS or IIS,
which is used to designate the sestertius. It stands either for LLS
(_Libra Libra et Semis_), or for IIS, the two I’s merely forming
the numeral two (sc. _asses_ or _librae_), and the whole being in
either case equivalent to _dupondius et semis_. When the as was
reduced to half an ounce, and the number of asses in the denarius
was made sixteen instead of ten [AS, DENARIUS], the sestertius was
still ¼ of the denarius, and therefore contained no longer 2½, but
4 asses. The old reckoning of 10 asses to the denarius was kept,
however, in paying the troops. After this change the sestertius was
coined in brass as well as in silver; the metal used for it was that
called _aurichalcum_, which was much finer than the common _aes_, of
which the asses were made. The sum of 1000 _sestertii_ was called
_sestertium_. This was also denoted by the symbol HS, the obvious
explanation of which is “IIS (2½ millia).” The _sestertium_ was
always a sum of money, never a _coin_; the _coin_ used in the payment
of large sums was the denarius. According to the value we have
assigned to the DENARIUS, up to the time of Augustus, we have--
_£. s. d. farth._
the sestertius = 0 0 2 ·5
the sestertium = 8 17 1
After the reign of Augustus--
the sestertius = 0 0 1 3·5
the sestertium = 7 16 3
The sestertius was the denomination of money almost always used in
reckoning considerable amounts. There are a very few examples of the
use of the denarius for this purpose. The mode of reckoning was as
follows:--_Sestertius_ = _sestertius nummus_ = _nummus_. Sums below
1000 _sestertii_ were expressed by the numeral adjectives joined with
either of these forms. The sum of 1000 sestertii = _mille sestertii_
= M _sestertium_ (for _sestertiorum_) = M _nummi_ = M _nummum_
(for _nummorum_) = M _sestertii nummi_ = M _sestertium nummum_ =
_sestertium_. These forms are used with the numeral adjectives below
1000: sometimes _millia_ is used instead of _sestertia_: sometimes
both words are omitted: sometimes _nummum_ or _sestertium_ is added.
For example, 600,000 sestertii = _sescenta sestertia_ = _sescenta
millia_ = _sescenta_ = _sescenta sestertia nummum_. For sums of a
thousand _sestertia_ (_i.e._ a million _sestertii_) and upwards,
the numeral adverbs in _ies_ (_decies, undecies, vicies, &c._) are
used, with which the words _centena millia_ (a hundred thousand) must
be understood. With these adverbs the neuter singular _sestertium_
is joined in the case required by the construction. Thus, _decies
sestertium_ = _decies centena millia sestertium_ = _ten times a
hundred thousand sestertii_ = 1,000,000 sestertii = 1000 _sestertia_:
_millies_ HS = _millies centena millia sestertium_ = a thousand times
one hundred thousand sestertii = 100,000,000 _sestertii_ = 100,000
_sestertia_. When the numbers are written in cypher, it is often
difficult to know whether _sestertii_ or _sestertia_ are meant. A
distinction is sometimes made by a line placed over the numeral when
_sestertia_ are intended, or in other words, when the numeral is an
adverb in _ies_. Thus
HS. M.C. = 1100 sestertii, but
HS. M̄.C̄. = HS millies centies
= 110,000 sestertia
= 110,000,000 sestertii.
_Sesterce_ is sometimes used as an English word. If so, it ought
to be used only as the translation of _sestertius_, never of
_sestertium_.