Part v; for we actually find him declaring (and it is pleasant to hear him)

that 'natheles, thise ben observauncez of iudicial matiere & _rytes of payens, in which my spirit ne hath no feith_'; ii. 4. 36; (p. 192).

§ 25. SOURCES OF THE TREATISE. I next have to point out the sources whence Chaucer's treatise was derived. Mr. Halliwell, in a note at the end of his edition of Mandeville's Travels, speaks of the original treatise on the Astrolabe, written in Sanskrit, on which he supposes Chaucer's treatise to have been founded. Whether the Latin version used by Chaucer was ultimately derived from a Sanskrit copy or not, need not be considered here. The use of the Astrolabe was no doubt well known at an early period in India and among the Persians and Arabs; see the 'Description of a Planispheric Astrolabe constructed for Sháh Sultán Husain Safawí, King of Persia,' by W. H. Morley, in which elaborate and beautifully illustrated volume the reader may find sufficient information. Marco Polo says (bk. ii. c. 33) that there were 5000 astrologers and soothsayers in the city of Cambaluc, adding--'they have a kind of _Astrolabe_, on which are inscribed the planetary signs, the hours, and critical points of the whole year'; Marco Polo, ed. Yule, i. 399. Compare also the mention of the instrument in the 161st night of the Arabian Nights' Entertainments, where a translation which I have now before me has the words--'instead of putting water into the basin, he [the barber] took a very handsome astrolabe out of his case, and went very gravely out of my room to the middle of the yard, to take the height of the sun'; on which passage Mr. Lane has a note (chap. v. note 57) which Mr. Brae quotes at length in his edition. There is also at least one version of a treatise in Greek, entitled [Greek: peri tês tou astrolabou chrêseôs], by Johannes Philoponus, of which the Cambridge University Library possesses two copies, viz. MSS. Dd. 15. 27 and Gg. 2. 33. But it is clear, from his own words, that Chaucer followed the Latin, and I can point out[52] one of the Latin treatises to which he was very considerably indebted. This is the 'Compositio et Operatio Astrolabie,' by Messahala[53], of which copies are, I have no doubt, sufficiently numerous. The Cambridge Library has four, viz. Hh. 6. 8, Ii. 1. 13, Ii. 3. 3[54], and Kk. 1. 1, and there is another copy in St. John's College Library, Cambridge, marked F. 25. The title should be particularly observed; for the treatise is distinctly divisible into two separate parts, viz. the 'Compositio Astrolabii' and the 'Operatio Astrolabii.' The former begins with the words--'Scito quod astrolabium sit nomen Graecum,' and explains how to make an astrolabe, and how to inscribe on it the various necessary lines and circles with sufficient exactness. It is much the longer portion of the treatise, and (in MS. Ii. 3. 3) is illustrated by numerous diagrams, whilst the second part has no such illustrations. But it does not appear that Chaucer made any use of this former part, as his astrolabe had been procured ready-made. The second part of the treatise, or 'Operatio Astrolabii,' begins with the words 'Nomina instrumentorum sunt hec.' This is evidently one of the sources from which Chaucer drew largely[55]. Chaucer's Part i. is almost wholly taken from this, but he has expanded it in several places, with the evident intention of making it more easy to understand. In Part ii. he has taken from it, with more or less exactness, sections 1-3, 5-8, 10, 11, 13-18, 20, 21, 24, 25, 27-31, 33-37, 41 and 42; whilst sections 4, 9, 12, 19, 22, 23, 26, 32, 38-40 and 43 do not appear in it. In other words, Messahala's treatise accounts for thirty-one conclusions out of forty-three, or about _two-thirds_ of the whole. In some places, Chaucer has translated almost word for word, so as to leave no doubt as to his authority. Besides which, I have already remarked that Chaucer's version is _directly_ connected with Messahala by the quotations from the latter which appear in MS. E.; see description of this MS. at p.