e Index of books prohibited to Christians.

The edition of the Index published in 1819 was as inexorable toward the
works of Copernicus and Galileo as its predecessors had been; but in the
year 1820 came a crisis. Canon Settele, Professor of Astronomy at Rome,
had written an elementary book in which the Copernican system was taken
for granted. The Master of the Sacred Palace, Anfossi, as censor of the
press, refused to allow the book to be printed unless Settele revised
his work and treated the Copernican theory as merely a hypothesis. On
this Settele appealed to Pope Pius VII, and the Pope referred the matter
to the Congregation of the Holy Office. At last, on the 16th of August,
1820, it was decided that Settele might teach the Copernican system as
established, and this decision was approved by the Pope. This aroused
considerable discussion, but finally, on the 11th of September, 1822,
the cardinals of the Holy Inquisition graciously agreed that "the
printing and publication of works treating of the motion of the earth
and the stability of the sun, in accordance with the general opinion of
modern astronomers, is permitted at Rome." This decree was ratified by
Pius VII, but it was not until thirteen years later, in 1835, that there
was issued an edition of the Index from which the condemnation of works
defending the double motion of the earth was left out.

This was not a moment too soon, for, as if the previous proofs had not
been sufficient, each of the motions of the earth was now absolutely
demonstrated anew, so as to be recognised by the ordinary observer.
The parallax of fixed stars, shown by Bessel as well as other noted
astronomers in 1838, clinched forever the doctrine of the revolution of
the earth around the sun, and in 1851 the great experiment of Foucault
with the pendulum showed to the human eye the earth in motion around its
own axis. To make the matter complete, this experiment was publicly made
in one of the churches at Rome by the eminent astronomer, Father Secchi,
of the Jesuits, in 1852--just two hundred and twenty years after the
Jesuits had done so much to secure Galileo's condemnation.(75)

(75) For good statements of the final action of the Church in the
matter, see Gebler; also Zoeckler, ii, 352. See also Bertrand,
Fondateurs de l'Astronomie moderne, p. 61; Flammarion, Vie de Copernic,
chap. ix. As to the time when the decree of condemnation was repealed,
there have been various pious a