266 
is indicated, the year finding in one of those points a natural 
beginning, which is regularly computed from the intercalary 
day by which it is immediately preceded—the author proceeds 
to show that the intercalation could not have been thus sug- 
gested, or have been originally coincident with the sun’s 
ingress into one of those points which divide the year into 
seasons. ‘This position he proceeds to prove by contrasting 
the time of the intercalation, as received from tradition, with 
that of the equinox as occurring between the extreme dates of 
the construction of the Egyptian calendar, B.C. 1711, and of 
the Roman, B.C. 45. Within that period, in which the inter- 
calation occurred at the close of February, the equinox tra- 
versed from April 6 to March 24, according to the computation 
of these dates by the Julian year anticipated. Having shown 
that the same conclusion must be formed of the four tropes of 
the year, as identified by Sosigenes with the 8th of the 
Kalends of April, July, October, and January, whereas the 
intercalation was fixed for the 6th of the Kalends of March, it is 
thence decided that it could not have originated from any such 
coincidence. 
The author, following up a suggestion of Eudoxus, pre- 
served by the astronomer Geminus, by which the natural di- 
vision of the year by the tropes is associated with the festival 
of the Isea, thence assumes that it discloses the probable 
grounds on which the day of the intercalation was chosen. 
After investigating the day on which the festival was held, 
and reducing the date of it, in the vague year of the Egyp- 
tians, to the coincident date of the Julian, he determines that 
in the year B.C. 1904, to which the epoch of the Egyptian 
calendar must be referred, the Isea fell on February 26. From 
this extraordinary coincidence in that remarkable year, he con- 
cludes that it discloses the original day of the intercalation, 
and the grounds on which it was chosen by the Egyptians. 
He thence takes occasion to prove the conformity of the fes- 
tival with the time of the harvest in Egypt, at which it was 
