The moon's distance he computed at 60⅓ semidiameters of the earth.
At this time it was a dangerous innovation to publish any but the vaguest astronomical facts, and as Copernicus had some anxiety as to how his statement would be received, his friend Rheticus published a volume, giving a preliminary account of the Copernican theory. Although the Papal authorities did not like the work of Copernicus, it only received their qualified disapprobation, for they put it on the index "subject to correction." However, although Copernicus stands as the first of the modern astronomers, he wrote very much in the same mystical strain as his predecessors, and was by no means like an astronomer of the nineteenth century. What he really appears to have done was to establish a precedent for the open publication of genuine observations, which even the gentle discouragement of the inquisitors was unable to suppress. Whether the measures of the planetary system, which he published, were derived from his own observations, or were only the revelation of an existing tradition, it is difficult to determine. But as he is said to have died without ever seeing his planet Mercury, presumably he could have made no observations as to the distances of this planet, and consequently must have received his data from some one else. This would imply, that the astronomers before his time knew the distances of the other planets, as well as that of Mercury. Again, if it were possible for Copernicus to arrive at the correct proportions of the universe without a telescope, and unaided by any previous observations beyond those which were published, we can see no reason for disbelieving, that the ancients, who are alleged to have gazed at the stars for thousands of years, were incapable of coming to a similarly accurate conclusion.
C
