265 
the reformation, and was that succeeding the consulship of 
Cesar and Lepidus. On being reduced to its proper place in 
the Julian Period, and its position in the solar cycle deter- 
mined, it is found to be the first year of its sixth quadrien- 
nium; and, thus coinciding with the epoch of the Julian 
years, numbered from it in succession, it necessarily deter- 
mines the quadrienniums derived from it to have been of the 
same character. 
From the account of Cesar’s reformation an evidence is 
deduced of the antiquity of the order assigned in his Calendar 
to the quadrienniums, as corresponding with those in the 
Julian Period. In tracing the usage to the times of Cn. Fla- 
vius, by whom it. was divulged in the consulate of P. Sulpi- 
cius Severus and P. Sempronius Sophus, the author shows 
that it preceded, by 259 years, the date of Cesar’s reformation. 
An example is thence elicited from Livy of the intercalation 
of the lustrum in the year B.C. 169; from whence it appears 
that the quadrienniums so termed were disposed in the order 
which they occupy in the Julian Period, as derived from the 
year as reformed by Cesar. To this example another is added, 
which is founded on an emendation of the text of Censorinus, 
as corrected from Pliny, and from which, if admitted, a like 
result follows—that from the reign of Servius Tullius to that 
of Vespasian, evidence occasionally appears of the succession 
of lustrums having conformed to the common order of the 
quadriennums in the Julian Period, although great license was 
used in departing from it on particular occasions. 
3. In the third and last division of his inquiry the author 
proceeds, from determining the year, to ascertain the day of 
the intercalation, which, as falling in the Julian year on the 
6th of the calends of March, corresponding with February 24, 
_ has acquired, from its being repeated at the end of the qua- 
driennium, the name of bissextile. 
After premising that by the sun’s entrance into one of the 
__ tropes, or cardinal points—the natural place of the intercalation 
4 
