4to. [20.5 x 15.5 cm], (4) ff., 227 (1) pp., (2) ff., including 5 woodcut figures and numerous geometrical illustrations in text, and with 1 folding plate. Bound in contemporary publisher’s cartonnage, title stenciled on spine; soiled, extremities bumped. Title toned, some light even browning or light foxing, faint waterstain in a few margins, blank margin of pp. 89/90 repaired; generally a very fresh copy.
Scarce augmented edition of this work on the theory of machines and the nature of gravity by the young Jesuit Paolo Casati. The work imaginatively envisions a Latin dialogue between three great physicists of the preceding generation, all recently dead in the 1640s: Galileo; Marin Mersenne, his greatest champion outside of Italy, and Paul Guldin, the leading Jesuit physicist at the Collegio Romano during the same period. Described here are numerous experiments for ascertaining the true weight and dimension of the earth, including one which concludes that water is drastically heavier than was commonly believed. Its contemporary impact is not known, but according to Thorndike (VIII.179), Casati was read by Robert Boyle. The present edition is more than four times the length of the 1655 first edition, which was a thesis presented viva voce at the Collegio Romano.
That a work sympathetic to Galileo, the arch rival of the Jesuits, should be printed in Rome, the intellectual capital of the Order, suggests that the power of Galileo’s condemnation was already waning, and that in areas other than astronomy, public adherence to Galileian views was becoming increasingly acceptable. This work appeared just two years after the first collected edition of Galileo’s Opera (Bologna, Dozza, 1656-55).
Casati (1617-1707) is an interesting and understudied figure in Jesuit intellectual life in the generation after Galileo. He is best known as the principal “handler” of Queen Cristina’s highly politicized conversion to Catholicism, leaving no doubt about his orthodoxy. He also wrote a work on a Galileian-style proportional compass and is credited by Baldini as a champion of Galileian mechanics, on which he lectured in Rome; see “L’attività scientifica nel primo Settecento,” Storia d’Italia. Einaudi Annali 3 (Turin 1980) 469 ff.).
* Cinti 134; Backer Sommervogel II, 800.3; Riccardi I, 270.2; not in Roberts & Trent; DBI XXI.265-6; Carli-Favaro 259; Sotheran 6750 (quoting Libri-Cinti, 134).