vens. So
great was the preference given to sacred over profane learning that
Christianity had been in existence fifteen hundred years, and had not
produced a single astronomer.

The Mohammedan nations did much better. Their cultivation of science
dates from the capture of Alexandria, A.D. 638. This was only six years
after the death of the Prophet. In less than two centuries they had
not only become acquainted with, but correctly appreciated, the Greek
scientific writers. As we have already mentioned, by his treaty with
Michael III., the khalif Al-Mamun had obtained a copy of the "Syntaxis"
of Ptolemy. He had it forthwith translated into Arabic. It became at
once the great authority of Saracen astronomy. From this basis the
Saracens had advanced to the solution of some of the most important
scientific problems. They had ascertained the dimensions of the earth;
they had registered or catalogued all the stars visible in their
heavens, giving to those of the larger magnitudes the names they still
bear on our maps and globes; they determined the true length of the
year, discovered astronomical refraction, invented the pendulum-clock,
improved the photometry of the stars, ascertained the curvilinear
path of a ray of light through the air, explained the phenomena of the
horizontal sun and moon, and why we see those bodies before they have
risen and after they have set; measured the height of the atmosphere,
determining it to be fifty-eight miles; given the true theory of the
twilight, and of the twinkling of the stars. They had built the first
observatory in Europe. So accurate were they in their observations, that
the ablest modern mathematicians have made use of their results.
Thus Laplace, in his "Systeme du Monde," adduces the observations of
Al-Batagni as affording incontestable proof of the diminution of the
eccentricity of the earth's orbit. He uses those of Ibn-Junis in his
discussion of the obliquity of the ecliptic, and also in the case of the
problems of the greater inequalities of Jupiter and Saturn.

These represent but a part, and indeed but a small part, of the services
rendered by the Arabian astronomers, in the solution of the problem of
the nature of the world. Meanwhile, such was the benighted condition of
Christendom, such its deplorable ignorance, that it cared nothing
about the matter. Its attention was engrossed by image-worship,
transubstantiation, the merits of the saints, miracles, shrine-cures.