Historians of science know Giovanni Battista Riccioli’s Almagestum Novum (Bologna, 1651) above all for one thing: the most exhaustive weighing of the Copernican question its century produced — the double catalogue cited ever since as Riccioli’s 126 arguments concerning the motion of the Earth, the arguments for set against the arguments against, each stated in its strongest form and each answered.
Until now, English readers have had only excerpts and summaries. The whole of it may now be read here, in context, in the first complete English translation of Book IX:
- Chapter XXXIII — the epitome of the arguments for the diurnal and annual motion of the Earth, with their solutions;
- Chapter XXXIV — the epitome of the arguments for the Earth’s immobility, with the Copernican solutions of very many of them;
- Chapter XXXV — the conclusion: which hypothesis must be asserted, “from mere reasons, all authority set aside.”
And these epitomes only summarize what the preceding thirty chapters argue at full length — from the physics of falling bodies to the parallax of the fixed stars. The whole of Book IX is here, free, with the original Latin linked from the work’s page.