Transcriber’s Notes: Underscores “_” before and after a word or phrase indicate _italics_ in the original text. Small capitals have been converted to SOLID capitals. Illustrations have been moved so they do not break up paragraphs. Old or antiquated spellings have been preserved. Typographical errors have been silently corrected. The table “TIME REFERENCES IN THE DIVINE COMEDY” on pages 358-366 has been reformatted from horizontal to vertical in order to better fit the 72-column format. Footnotes have been separated out from the main text by the use of lines above and below, made of hyphens. [Illustration: DANTE STUDYING. _Frontispiece_ _From a fresco by Luca Signorelli at Orvieto._ Or vedi insieme l’uno e l’altro polo, Le stelle vaghe e lor viaggio torto; E vedi ’l veder nostro quanto è corte. _Petrarch._] DANTE AND THE EARLY ASTRONOMERS BY M. A. ORR (MRS. JOHN EVERSHED). Plainness and clearness without shadow of stain, Clearness divine! Ye heavens, whose pure dark regions have no sign Of languor, though so calm, and though so great Are yet untroubled and unpassionate; Who, though so noble, share in the world’s toil, And though so tasked keep free from dust and soil! * * * * * You remain A world above man’s head, to let him see How boundless might his soul’s horizons be, How vast, yet of what clear transparency. MATTHEW ARNOLD. London GALL AND INGLIS, 31 HENRIETTA ST., W.C. _And Edinburgh._ PRINTED AND BOUND BY GALL AND INGLIS, NEWINGTON PRINTING AND BOOKBINDING WORKS, EDINBURGH. PREFACE. An observatory on a mountain top is an ideal place in which to write on astronomy and poetry, but it has one drawback: the difficulty of obtaining books on special subjects. My husband’s criticisms and help have been invaluable, and of books on modern astronomy there is no lack; but many others which I have wished to consult I have been unable to procure, and doubtless there are many more which I ought to have read, but of whose existence I am ignorant. This defect has been partly remedied, however, by Mr. Wicksteed’s great kindness in lending me a number of books on Dante subjects. I am much indebted to my sister, Miss Orr, who has helped me in preparing these sheets for the press. The index is mainly her work.