Page:On the Difficulty of Correct Description of Books - De Morgan (1902).djvu/23

 a table of contents, at the end of which is "Quibus omnibus arithmeticorum libri duo demum accesserunt." This is conclusive as to one difficulty, but it introduces another. The word demum usually indicates that the edition in question is not the first; at last, we are told, the two books of arithmetic are added. Either then there are previous editions without the arithmetic, or at last the arithmetic is added, and a new title-page, probably of later date, printed before all. Nevertheless, we can find no indication of any earlier edition or earlier title-page. None is mentioned; the arithmetic [13] now under consideration has in it a list of works, distinguishing and dating those which were printed, but not containing anything to our present purpose. The maker of a catalogue would be compelled to raise the doubt of a second edition, or of a title-page with a new date, unless he happened to know that Maurolycus died in 1575. We now learn the meaning of demum: the work had been waiting for the arithmetic, which the author could not or would not finish, and his death at last enabled the publisher to obtain the manuscript, and complete the undertaking. This view of the case is enforced by our finding the arithmetic wholly destitute of preface or introduction, and with some gaps in the manuscript.

These circumstances, apparently so unimportant, help to decide an historical question which is not without interest. We have seen that the Cosmographia has a passage which indicates a lurking fear that the doctrine of the earth's motion was likely to be maintained. Though, by 1543, there was plenty of time to become aware of Rheticus's announcement of Copernicus, yet Maurolycus tells us, with the utmost definiteness, at the end, that the work was "finished at Messina, in the straits of Sicily, on Thursday, October 21, indiction ix, in the year of grace 1535, being the day on which the Cæsar, Charles V., returned to Messina from his African expedition." May we, in