§ 20. The last five sections spurious. This at once suggests two results. The first is, that, as this gives two sets of sections on the 'umbrae,' we can hardly expect both to be genuine; and accordingly, we at once find that the last five of these are mere clumsy repetitions of the first three; for which reason, I unhesitatingly reject the said last five as spurious. This view is strikingly confirmed by MS. P.; for this, the only first-class MS. that is carried on beyond section 40, contains the first three sections on the 'umbrae' only. The second result is, that if the first three sections on the 'umbrae' are to be received, there is good reason why we should consider the possible genuineness of sections 44 and 45 on the 'mene mote,' which rest very nearly on the same authority.
Now the sections on the 'mene mote' have in their favour one strong piece of internal evidence; for the date 1397 is mentioned in them more than once as being the 'root' or epoch from which to reckon. In most cases, the mention of a date 1397 would lead us to attribute the writing in which it occurs to that year or to a later year, but a date fixed on for a 'root' may very well be a prospective one, so that these sections may have been written before 1397; an idea which is supported by the line 'behold whether thy date be more or lasse than the yere 1397'; sect. 44, l. 5. But I suspect the date to be an error for 1387, since that [see Somer in Tyrwhitt's Glossary] was really the 'rote' used by Nicholas Lenne. In either case, I think we may connect these sections with the previous sections written in 1391[[47]]. Besides which, Chaucer so expressly intimates his acquaintance with the subjects of these sections in the Canterbury Tales[[48]], that we may the more readily admit them to be really his. There is still less difficulty about admitting the first three sections (41-43) on the 'umbrae,' because we find similar matter in the treatise of Messahala, from which, as will appear, he derived so much. And hence we may readily conclude that, in the second part, the first forty sections, found in the oldest MSS., are certainly genuine, whilst sections 41-43, as well as 44 and 45, have every claim to be considered genuine also. This need not, however, force us to accept the remaining sections, since they may easily have been added by another hand; a circumstance which is rendered the more probable by the fact that sections 41a-42b merely repeat 41-43 in a more clumsy form, and by the consideration that, if genuine, they should have occupied their proper place immediately after sect. 43, instead of being separated from the former set. As to sect. 46, I pronounce no decided opinion; there is but little to be said either for or against it, and it is of little consequence.
§ 21. Gap between §§ 40 and 41. But admitting the genuineness of sections 40-45, it at once becomes evident that there are two distinct gaps or breaks in the continuity of the treatise; the first between 40 and 41; and the second between 43 and 44. A little consideration will account for these. Looking at the Canterbury Tales, we observe the very same peculiarity; at certain points there are distinct breaks, and no mending can link the various groups together in a satisfactory manner. This can be accounted for in part by our knowledge of the fact that the poet died before he had completed the proper linking-together of the tales which he had more or less finished; but I think it also shews him to have been a fragmentary worker. To suppose that, upon reaching Conclusion 40, he suddenly turned to the sections upon the 'umbrae,' which are at once more easy to explain, more suitable for a child, and illustrative of a different and more practical use of the Astrolabe, seems to me natural enough; and more probable than to suppose that anything is here lost. For, in fact, it is to the very MSS. that contain sections 41-43 that we are indebted for the last five words of sect. 40, so curiously omitted in the oldest and best MSS.; and this is a direct argument against the supposition of any matter having been here lost.
§ 22. Gap between §§ 43 and 44. The break between sections 43 and 44 may be explained in a totally different manner. In this case, the break indicates a real, not an accidental, gap. I suppose section 43 to have been really the last section of Part ii, and I refer sections 44 and 45 to the Fourth Part of the Treatise, and not to the Second at all[[49]]. For if we run through the contents of Parts Three and Four (p. [177]), we observe that they chiefly involve tables, with reference to one of which we find the words 'upon which table ther folwith a canon,' &c. Now sections 44 and 45 exactly answer the description; they are alternative canons, shewing how certain tables may be used. It happens that Conclusion 40 is particularly dependent upon tables. To supply these was partly the object of Part iv—'the whiche ferthe partie in special shal shewen a table of the verray moeving of the mone from houre to houre, every day and in every signe, after thyn almenak; upon which table ther folwith a canon, suffisant to teche as wel the maner of the wyrking of that same conclusioun, as to knowe in oure orizonte with which degree of the zodiac that the mone ariseth in any latitude; and the arising of any planete after his latitude fro the ecliptik lyne.' The opening words of the same Conclusion are—'Knowe by thyn almenak the degree of the ecliptik of any signe in which that the planete is rekned for to be:' (p. [221]). This is easily said; but I suppose that it was not so easy in olden times to know off-hand the exact position of a planet. It must have been shewn by tables, and these tables chiefly considered the 'mene mote,' or average motion of the planets, and that only for periods of years. If you wanted the position of a planet at a given hour on a given day, you had to work it out by figures; the rule for which working was called a 'canon.' This very 'canon' is precisely given at length in sect. 44; and sect. 45 is only another way of doing the same thing, or, in other words, is an alternative canon. When all this is fairly and sufficiently considered, we shall find good grounds for supposing that these sections on the 'mene mote' are perfectly genuine, and that they really belong to Part iv. of the Treatise.
I will only add, that the fact of sections 41a-42b being thus placed after a portion of Part iv. is one more indication that they are spurious.
§ 23. Conclusion 40. But it may be objected, as Mr. Brae has fairly objected, that Conclusion 40 itself ought to belong to Part iv. So it ought perhaps, if Chaucer had followed out his own plan. But it is clear from its contents that the Prologue to the 'Astrolabie' was written before the commencement of the treatise itself, and not, as prefaces generally are, afterwards. He was pleased with his son's progress. Little Lewis had asked him if he might learn something about an astrolabe. The father at once sent him a small astrolabe[[50]] by way of reward, constructed for the latitude of Oxford, and having 45 circles of latitude on the flat disc (see [Fig. 5]) instead of having 90 such circles, as the best instruments had[[51]]. This, however, was a 'sufficient' astrolabe for the purpose. But he believes the Latin treatises to be too hard for his son's use, and the Conclusions in them to be too numerous. He therefore proposes to select some of the more important Conclusions, and to turn them into English with such modifications as would render them easier for a child to understand, He then lays down a table of contents of his proposed five parts, throughout which he employs the future tense, as 'the firste partie shal reherse,'—'the second partie shal teche,' &c. This use of the future would not alone prove much, but taken in connexion with the context, it becomes very suggestive. However, the most significant phrase is in the last line of the Prologue, which speaks of 'other noteful thinges, yif god wol vouche-sauf & his modur the mayde, mo than I behete,' i.e. other useful things, more than I now promise, if God and the Virgin vouchsafe it. In accordance with his habits of seldom finishing and of deviating from his own plans at pleasure, we have but an imperfect result, not altogether answerable to the table of contents. I therefore agree with Mr. Brae that the 40th Conclusion would have done better for Part iv., though I do not agree with him in rejecting it as spurious. This he was led to do by the badness of the text of the MSS. which he consulted, but we can hardly reject this Conclusion without rejecting the whole Treatise, as it is found in all the oldest copies. By way of illustration, I would point out that this is not the only difficulty, for the Conclusions about astrology ought certainly to have been reserved for Part v. These are Conclusions 36 and 37, which concern the 'equaciouns of houses'; and this is probably why, in three of the MSS. (viz. L., N., and R.), these two conclusions are made to come at the end of the Treatise. There is nothing for it but to accept what we have, and be thankful.
§ 24. Extant portion of the Treatise. If, then, the questions be asked, how much of the Treatise has come down to us, and what was to have been the contents of the missing portion, the account stands thus.
Of Part i. we have the whole.
Of Part ii. we have nearly all, and probably all that ever was written, including Conclusions 1-40 on astronomical matters, and Conclusions 41-43 on the taking of altitudes of terrestrial objects. Possibly Conclusion 46 is to be added to these; but Conclusions 41a-42b are certainly spurious.
Part iii. probably consisted entirely of tables, and some at least of these may very well have been transmitted to little Lewis. Indeed, they may have been prepared by or copied from Nicholas of Lynn and John Somer, before Chaucer took the rest in hand. The tables were to have been (and perhaps were) as follows:—