He believes that as far back as 30,000 B.C., hunters may have used a system of notation, engraved on bone and stone, to mark phases of the Moon.
他认为，远在公元前30,000年以前，猎人可能会用一套刻在骨头和石头上的符号系统来标记月相。
2
In its original state, there were rotating dials and other indicators on the top, with letters and drawings showing the Sun, the phases of the moon and different constellations.
最初，它的顶部有旋转的刻度盘和其他指示物，上面的字母和图画描绘了太阳、月相和不同的星座。
3
This article focuses on the first three phases of this process.