The Equatorie of the Planetis

[5] The Equatorie occupies eight leaves of the manuscript; the phrase Radix chaucer appears on fol.

[2] The manuscript has been digitised for the Cambridge University Digital Library website, together with a virtual model of the equatorium.

[7] However, John North argued that the attachment of a name to a relatively "trivial" piece of data made it likely that this was a case of self-citation.

[12] This was a controversial claim, and was treated with some scepticism by Chaucer scholars,[13] though it received influential backing from the historian of astronomy John North.

[21] Price offered five points as indicators of Chaucer's authorship:[19] Following the publication of the facsimile and transcription, G. Herdan published an article in which he concluded, based upon the percentage of words in the Equatorie of "Romance vocabulary" (which includes words from Old French, Anglo-Norman French, and Latin), that Chaucer was indeed the author: "The agreement between observation and expectation, or between fact and theory, is so striking that without going further into the question of statistical significance we may conclude that by the token of Romance vocabulary the Equatorie is to be regarded as a work by Chaucer".

His claim that the manuscript was a draft in the hand of its author was disputed,[13] though ultimately the evidence does seem to support it.

[23] More significantly, Price's claim that the handwriting was that of Geoffrey Chaucer was disproved by analysis by Kari Anne Rand Schmidt.

One of them is solid, and is marked with characteristics of the orbits of the various planets: their apogee, their equants, and other centres.

[26] It permits the user to find the longitudes of any classical planet (including the Sun and Moon, as well as the lunar latitude).

He could not, however, discern what the rationale of or the ordering behind the key was – whether it was perhaps based on some medieval version of the Greek alphabet, or whether there was "some key-phrase or sentence such as a name or family motto" behind it.