Year 300 ce

Astronomy

Chinese astronomer Chen Zhuo combines the star maps produced by Shih Shen, Gan De, and Wu Xien in the fourth century bce into a single map. See also 150 bce Astronomy.

The Maya develop the daycount calendar, which combines the 365-day Olmec calendar that has a 52-year cycle with the 260-day cycle known as the tzolkin, which has 13 cycles of 20 days each. This is used to date events back to 3000 bce (the earlier events are thought to have been legends or myths). See also 200 ce Construction.

The Greek alchemist Zosimos of Panopolis summarizes the available work of hundreds of Egyptian alchemists. Although most of his book is pure mysticism, he describes what is apparently arsenic and lead acetate, both for the first time. About this time also, Roman emperor Diocletian orders destruction of alchemical books and manuscripts for fear that success in making gold from base metals would debase the currency. See also 100 ce Chemistry; 400 ce Chemistry.

Extrapolation from later developments suggests that the Maya are beginning to develop written books. See also 600 ce Communication.

The palace of Diocletian at Spalatum (Split, Croatia), built about this time, uses arches supported by freestanding columns, a device that becomes common in medieval architecture. See also 100 ce Construction.

By this time bellows are in use in Europe to produce higher quality iron. Bellows had been producing cast iron in China for about 600 years and had been used in the Near East as early as 1600 bce. See also 31 ce Tools.

The earliest known knitted fabrics date from about this time, although net-making, the ancestor of knitting, seems to go back to Neolithic times. See also 7500 bce Materials.

The Chinese learn to use coal instead of wood as the fuel in making cast iron. See also 1611 ce Materials.

About this time the Chinese may have begun to develop the abacus, although the first printed reference to one comes in 1593 ce. See also 500 ce Mathematics.