4. See fig. 1; Chaucer describes the 'bak-half' of the instrument first. The centre of the 'large hole amydde' is the centre of the instrument, where a smaller hole is pierced completely through. The _Southe lyne_ (marked _Meridies_ in figs. 1 and 2) is also called _Linea Meridiei;_ the _North lyne_ is also named _Linea Mediæ Noctis_. 5. The _Est lyne_ is marked with the word _Oriens;_ the _West lyne_, with _Occidens_. 6. The rule is the same as in heraldry, the _right_ or _dexter_ side being towards the spectator's left. 7. As the 360 degrees answer to 24 hours of time, 15° answer to an hour, and 5° to twenty minutes, or a _Mile-way_, as it is the average time for walking a mile. So also 1° answers to 4 minutes of time. See the two outermost circles in fig. 1, and the divisions of the 'border' in fig. 2. 8. See the third and fourth circles (reckoning inwards) in fig. 1. 9. See the fifth and sixth circles in fig. 1. 10. See the seventh, eighth, and ninth circles in fig. 1. The names of the months are all Roman. The month formerly called _Quinctilis_ was first called _Julius_ in B.C. 44; that called _Sextilis_ was named _Augustus_ in B.C. 27. It is a mistake to say that Julius and Augustus made the alterations spoken of in the text; what Julius Cæsar really did, was to add 2 days to the months of January, August (Sextilis), and December, and 1 day to April, June, September, and November. February never had more than 28 days till he introduced bissextile years. 11. See the two inmost circles in fig. 1. The names given are adopted from a comparison of the figures in the Cambridge University and Trinity MSS., neither of which are quite correct. The letters of the 'Abc.' are what we now call the Sunday letters. The festivals marked are those of St. Paul (Jan. 25), The Purification (Feb. 2), The Annunciation (Mar. 25), The Invention of the Holy Cross (May 3), St. John the Baptist (June 24), St. James (July 25), St. Lawrence (Aug. 10), The Nativity of the Blessed Virgin (Sept. 8), St. Luke (Oct. 18), St. Martin of Tours (Nov. 11), and St. Thomas (Dec. 21). 12. The 'scale' is in Latin _Quadrans_, or _Scala Altimetra_. It is certain that Chaucer has here made a slip, which cannot be fairly laid to the charge of the scribes, as the MSS. agree in transposing _versa_ and _recta_. The side-parts of the scale are called _Umbra versa_, the lower part _Umbra recta_ or _extensa_. This will appear more clearly at the end of Part II. (I here give a _corrected text_.)