Unless Chaucer had intended to mark with particular exactness the day of
the journey to Canterbury, he would not have taken such unusual precautions
to protect his text from ignorant or careless transcribers. We find him not
only recording the altitudes of the sun, at different hours, in words; but
also corroborating those words by associating them with physical facts
incapable of being perverted or misunderstood.
Had Chaucer done this in one instance only, we might imagine that it was
but another of those occasions, so frequently seized upon by him, for the
display of a little scientific knowledge; but when he repeats the very same
precautionary expedient again, in the afternoon of the same day, we begin
to perceive that he must have had some fixed purpose; because, as I shall
presently show, it is the repetition alone that renders the record
imperishable.
But whether Chaucer really devised this method for the express purpose of
preserving his text, or not, it has at least had that effect,--for while
there are scarcely two MSS. extant which agree in the verbal record of the
day and hours, the physical circumstances remain, and afford at all times
independent data for the recovery or correction of the true reading.
The day of the month may be deduced from the declination of the sun; and,
to obtain the latter, all the data required are,