In addition to the MS. authorities, we have one more source of text, viz. the Editio Princeps, which may be thus described. Th.--The edition of Chaucer's Works by Wm. Thynne, printed at London by Thomas Godfray in 1532. This is the first edition in which the Treatise on the Astrolabe appeared; it begins at fol. ccxcviii, back. The Conclusions in Part ii. are in the order following, viz. 1-12, 19-21, 13-18, 22-40; after which come 41-43, and 41_a_-42_b_. This order does not agree precisely with that in any MS. now extant, with the exception of I., which imitates it. It has some corrupt additions and exhibits many grave errors. All later editions, down to Urry's in 1721, contribute no new information. The few slight alterations which appear in them are such as could have been made without reference to MSS. at all. § 19. REMARKS ON THE CLASSES OF THE MSS. On comparing the MSS., it at once appears that they do not agree as to the order of the Conclusions in Part ii. The MSS. A., B., C. (which are unquestionably the oldest), as well as E., F., G., and P., adopt the order which appears in this edition, but which has never appeared in any previous edition. In all other editions we find the three sections 19-21 made to precede sections 13-18. Now we might here appeal to authority only, and say that the order in the _oldest_ MSS. ought to be preferred. But it so happens that we can appeal to internal evidence as well, and there are two considerations which shew that the oldest MSS. are certainly correct. These are as follows. In the _first_ place, sect. 18 amounts to finding the degree of the zodiac which _souths_ with any star, and begins with the words 'Set the centre of the sterre upon the lyne meridional'; whilst sect. 19 amounts to finding the degree of the zodiac that _rises_ with any star, and begins with the words 'Set the sentre of the sterre upon the est orisonte.' Clearly, these Conclusions are closely linked together, and one ought to follow the other. But, in all the editions, this continuity is broken. In the _second_ place, the rubric of sect. 21 is--'To knowe for what latitude in any regioun,' &c.; whilst that of sect. 22 is--'To knowe in special the latitude of oure countray,' &c. Clearly, these Conclusions are closely linked, and in their right order. But, in all the editions, this continuity is again broken; and we have this absurd result, viz. that a proposition headed--'To knowe the degrees of the longitudes of fixe sterres' is followed by one headed--'To knowe _in special_ the latitude of oure countray.' Hence we are enabled to draw a line, and to divide the MSS. into two classes; those in which the order of sections is correct, and those in which it has suffered misplacement, the number in each class being much the same. This gives us the following result. _First Class._ A., B., C, (probably D.,) E., F., G., P. _Second Class._ H., I., K., L., M., N., O., R.; to which add Th.