Again, Folco of Marseilles, when describing his birthplace, says that the greatest of all the seas (the Mediterranean) except the ocean which encircles all the habitable earth, stretches so far against the sun (i.e. from west to east), that the line of sky which is on its horizon at one end is on its meridian at the other.[434] If the sun were seen just rising on the eastern horizon at Gades, it would be on the meridian at Jerusalem and the time would there be noon.
Dante’s hours are always reckoned from sunrise, and they are the “temporary” or Church hours. He defines both kinds in the Convivio. The same lines of his Ode which provided him with a text whereon to discourse of the sun’s movements, give him occasion to treat of the division of each day into hours, thus:—
“I say that the sun, in circling round the world, ne’er beholdeth aught so noble as this lady, from which it follows that she is, as the words affirm, the most noble of all the things on which the sun shines. And I say in that hour, etc. Wherefore we must know that the hour is understood in two senses by astrologers. One sense is employed when they assign twenty-four hours to the day and night, that is, twelve to the day and twelve to the night, however long or short the day may be. And these hours become short or long in the day and in the night, according as the day and night wax and wane. And the Church uses hours in this sense when she speaks of Prime, Tierce, Sext, and None; and these are called temporal hours. The other sense is employed when, of the twenty-four hours alloted to the day and night, the day has sometimes fifteen and the night nine, and sometimes the night has sixteen and the day eight assigned to it, according as the day and the night wax and wane; and these are called equal hours. And at the equinox these latter are always one and the same with those which are called temporal; for it must needs be so when the day and the night are of the same length.”[435]
The choice of these two examples of unequal days and nights seems to be another instance of Dante’s dependence upon Alfraganus, for in Chapter VIII. of the Elementa Astronomica we read that the middle of the seventh climate (in which the inequality is greatest) has a longest day of 16 hours, and the middle of the fifth, of 15 hours; and in chapter IX. we find that Magna Roma is situated in the fifth climate.
In the fourth treatise of the Convivio, Dante returns to the same subject, and enters into further detail about Church hours and divisions of the day.[436] Our lives, like the arch of heaven which is always above us, consist of a rise and a decline, with a culminating point, and this point he fixes as normally reached at a man’s 35th year, as Ristoro had also done.[437] In the same way the day rises and declines, and culminates at the sixth hour; and it is the most noble hour of the day and the most virtuous (in the old Latin sense of virtue as strength, efficacy).
“La sesta ora, cioè il mezzo del dì, è la più nobile di tutto il dì, e la più vertuosa.”[438]
This means the whole of the sixth hour (as we should say, from 11 to 12 o’clock): the beginning of the seventh hour is the exact moment of noon, after which the day begins to decline. It was for this reason, Dante believes, that Christ chose to die during the sixth hour,[439] and during his 34th year, for then the day and his human life were both at their culmination, and had not begun to decline.
There was some difference in the methods of reckoning the hours for Church offices, but Dante tells in this same passage which of them he considered right, and he follows it consistently in his works. The Church day was divided into four parts, viz.:—
| At the equinox= | ||
| Tierce, | Sunrise to the end of the third hour | 6 to 9 a.m. |
| Sext, | Fourth to end of sixth hour | 9 a.m. to 12 noon |
| Nones, | Seventh to end of ninth | 12 noon to 3 p.m. |
| Vespers, | Tenth hour to sunset | 3 to 6 p.m. |
Two of the Church offices were to be said at the beginning, and one at the end, of these periods, as follows:—