Besides his superb poetry, Geoffrey Chaucer, the fourteenth-century English poet, wrote a number of prose pieces, and one of these was entitled A Treatise on the Astrolabe. An astrolabe is a scientific instrument with which a user is able to determine information on the angle of altitude of a celestial body such as a star, a planet, the moon, or the sun. The astrolabe also reveals the height of a building or a hill as well as the depth of a well. Throughout most of the nineteenth century and the first part of the twentieth century, critics were very uncomfortable with the fact that a major British poet wrote a scientific treatise in prose. Science and poetry were believed to be so separate that a poet would overreach himself by dipping into science and a scientist would equally overreach himself by dipping into poetry. It is only in the last third of the twentieth century, and now in the beginning years of the twenty-first, that critics understand the close and significant relationship between the scientific information about which Chaucer writes and the poetry which delighted readers over so many years. With Time and the Astrolabe Professor Marijane Osborn joins a number of other forward-looking scholars in this new approach toward Chaucer. Scholars of the past century did not look on A Treatise on the Astrolabe as serious literature, although they often admired its scientific competence. They spent most of their energy explaining the technical aspects of the Astrolabe. W. W. Skeat's 1872 edition was thorough in telling the reader what an astrolabe is but said nothing about its effect on Chaucer's poetry. Thomas R. Lounsbury (1892) found it "quite dry," and George Saintsbury (1908) said it was "Clear, practical and to the purpose" but never acknowledged that it could have any significant relationship to Chaucer's poetry. Until about 1950, Chaucerians had very little use for A Treatise on the Astrolabe, but after that date, parallel to a new interest in exegetical criticism, Chaucer's scientific writings took on a fresh importance.
Perhaps the earliest serious interest in the astrolabe arose from the erroneous belief that A Treatise on the Astrolabe was an astrologer's essay and had little to do with astronomy. Astrology was of great interest early in the last century, and many stoutly held that Chaucer himself believed wholeheartedly in judicial astrology, that is astrology which predicts the future. Chaucer, however, was a devout Catholic, and a believer in freedom of the will, which judicial astrology denies. Chaucer could not have believed in judicial astrology any more than he believed in the Greek and Roman gods, although he used both astrology and classical mythology metaphorically in his poetry. The fact is, however, that until the late twentieth century, many scholars saw Chaucer as a lip-service Catholic who believed in astrology and whose scientific writings were an anomaly which did not deserve serious study.
In the late twentieth century a number of scholars offered some serious studies of Chaucer and astronomy, which, of course, is not to be confused with astrology. Foremost among them were J. D. North of Oxford and J. C. Eade of Canberra, Australia. Although others had hinted that Chaucer was using actual dates to pinpoint the events in his poetry, North and Eade thoroughly studied Chaucer's astronomy, which he used to reveal actual dates in his work, and then Chaucer's astrology, which, although he did not believe in the practice, was also used for dating. North, Eade, and others suggested that Chaucer's scientific writing could uncover hidden material in his poetry. With the publication of Time and the Astrolabe, Osborn joins this school of thinking.
In an opening section called "Bearings," Osborn begins her study of Chaucer and his astrolabe by considering Chaucer's sky, the Ptolemaic sky, that is a sky with the earth at the center and everything else in the sky revolving around the earth. Now Osborn turns to her first example in which the astrolabe is the basis for a tale told on the Canterbury journey. This is the Squire's Tale where a famous king, Cambyuskan, receives for his birthday a steed of brass which will do wondrous things. For instance, this steed will take its rider to any known place in the universe and will bring him home in a matter of seconds. The brass horse is, of course, an astrolabe, since an astrolabe will take its user to any visible point in the universe and will return him to his place of departure.
Next Osborn considers how an astrolabe may be used to solve a number of the little mysteries which appear on the Canterbury journey. Why, for instance, is the sun at the half-way point in the Ram, when the Sign of the Ram extended in Chaucer's day from about March 12 to April 12, leaving the half way point in late March? Yet Chaucer in the opening lines of the Canterbury Tales tells us that we are in April. In earlier days critics either ignored what they could not explain or suggested that Chaucer or some careless scribe made an error.
In a second section called "Applications," Osborn turns to the Knight's Tale, and we learn that the great amphitheater where Palamon and Arcite engage in their final battle was based in its entirety on an astrolabe. Like the amphitheater, an astrolabe is round, and it has directions on it corresponding to the points of the compass. Osborn, apparently, is the first to describe the amphitheater in this manner. She finishes the Knight's Tale by analyzing the prayers to the pagan deities and considering the Ptolemaic spheres. The remainder of the section on applications is concerned with the Miller's Tale and its parallels to the Knight's Tale.
The third and final section is called "Implications," and here Osborn again considers some of the knottier problems in The Canterbury Tales. Does Chaucer believe in judicial astrology? In A Treatise on the Astrolabe he says he does not, and Osborn takes him at his word. When she comes to Furnivall's nineteenth-century assertion that the Canterbury pilgrimage took four days, Osborn, who knows more recent scholarship thoroughly, agrees that the pilgrimage took place on one symbolic day from sunrise to sunset. Finally she turns to the passage in the Prologue to The Parson's Tale, where Chaucer apparently says that Libra is the Moon's exaltation, which it is not. Joining such eminent scholars as Chauncey Wood, Charlotte Thompson, J. C. Eade, and others, Osborn comes up with her own satisfactory analysis.
Time and the Astrolabe in the Canterbury Tales is carefully and thoroughly researched. This is no fluttering of the wings by a neophyte scholar. The thesis is original, and the scholarship is compelling. The book contains more than sixty black and white figures, many of which are drawn by Osborn. In an appendix she gives the reader directions and drawings for making his or her own photocopied astrolabe. The bibliography is full, and the notes are copious. With this book, Osborn has placed herself in the vanguard of the new Chaucerian scholarship. She is a fit successor to North, Eade, and Wood and has brought to all of us a new and valuable approach to Chaucer.