Note 407 — Chapter IX · THE SENTENCE AND RECANTATION.
G. (George) Sturge translation
The reproach which the apologists of the Inquisition are fond of bringing against Galileo, that he knew nothing about the specific gravity of the air, is incorrect, as appears from his letter to Baliani of 12th March, 1613 (published for the first time in 1864 by Signor Giuseppe Sacchi, director of the library at Brera, where the autograph letter is to be seen), in which Galileo describes a method he had invented for determining the specific gravity of the air.