Such evidence as we have would seem to make it probable that both manufactures had attained to considerable excellence in Chaldaean times.
The only sciences in which the early Chaldaeans can at present be proved to have excelled are the cognate ones of arithmetic and astronomy.

On the broad and monotonous plains of Lower Mesopotamia, where the earth has little upon it to suggest thought or please by variety, the "variegated heaven," ever changing with the hours and with the seasons, would early attract attention, while the clear sky, dry atmosphere, and level horizon would afford facilities for observations, so soon as the idea of them suggested itself to the minds of the inhabitants.

The "Chaldaean learning" of a later age appears to have been originated, in all its branches, by the primitive people; in whose language it continued to be written even in Semitic times.
We are informed by Simplicius that Callisthenes, who accompanied Alexander to Babylon, sent to Aristotle from that capital a series of astronomical observations, which he had found preserved there, extending back to a period of 1903 years from Alexander's conquest of the city.
Epigenes related that these observations were recorded upon tablets of baked clay, which is quite in accordance with all that we know of the literary habits of the people.

They must have extended, according to Simplicius, as far back as B.C.2234, and would therefore seem to have been commenced and carried on for many centuries by the primitive Chaldaean people.

We have no means of determining their exact nature or value, as none of them have been preserved to us: no doubt they were at first extremely simple; but we have every reason to conclude that they were of a real and substantial character.