20. Ascensional Difference, is the difference betwixt the right and oblique ascension or descension, and shews how long the Sun rises or sets before or after the hour of six.
IV. Of the Division of Time.
The parts that time is distinguished into, are Days, Hours, Weeks, Months, and Years.
A Day is either natural or artificial.
Natural and Artificial Day.
A Natural Day is the space of time elapsed while the Sun goes from any meridian or horary circle, ’till he arrives to the same again; or, it is the time contained from noon, or any particular hour, to the next noon, or the same hour again: An Artificial Day is the time betwixt the Sun’s rising and setting; to which is opposed the Night, that is, the time the Sun is hid under the horizon.
Hours, &c.
Equinoxes.
Vernal and Autumnal Equinox.
Solstices.