Footnote 77
Supp. Prop., §44.  This article and the next may possibly be Chaucer's.  It is well known that he speaks of `collect' and `expans yeres' and `rotes' in the Frankeleines Tale; Cant. Ta., F 1275, 6, the note upon which in the glossary to Urry's Chaucer may be found also in Tyrwhitt's Glossary, s. v. Expans; but it is worth while to repeat it here.  `In this and the following verses, the Poet describes the Alphonsine Astronomical Tables by the several parts of them, wherein some technical terms occur, which were used by the old astronomers, and continued by the compilers of those tables.  Collect years are certain sums of years, with the motions of the heavenly bodies corresponding to them, as of 20, 40, 60, &c.,  disposed into tables; and Expans years are the single years, with the motions of the heavenly bodies answering to them, beginning at 1, and continued on to the smallest Collect sum, as 20.  A Root, or Radix, is any certain time taken at pleasure, from which, as an era, the celestial motions are to be computed.  By `proporcionels convenientes' [C.T., F 1078] are meant the Tables of  Proportional parts.'  To which Moxon adds, from Chamber's Encyclopædia, with reference to C.T., F 1277, that `Argument in astronomy is an arc whereby we seek another unknown arc proportional to [or rather, dependent upon] the first.'

Tables of mean motions of the Sun are given in Ptolemy's Almagest, lib. iii. c. 2; of the Moon, lib. iv. c. 3; of the Planets, lib. viii. c. 3; also in MS. Ii. 3. 3, fol. 88b, &c.