116. _day naturel._ In his Treatise on the Astrolabe, pt. ii. c. 7 (see
vol. iii. p. 194), Chaucer explains that the day _artificial_ is the time
from sunrise to sunset, which varies; to which he adds--'but the _day
natural_, that is to seyn 24 houres, is the revolucioun of the equinoxial
with as moche partie of the zodiak as the sonne of his propre moevinge
passeth in the mene whyle.' See note to B. 2.