Before the time of Thales it was, of course only the visible and apparent risings and settings of the signs that were the subject of observation. But astronomers now learned to distinguish these phenomena into three kinds. These they termed the cosmic, acronych, and heliac ris...
Before the time of Thales it was, of course only the visible and apparent risings and settings of the signs that were the subject of observation. But astronomers now learned to distinguish these phenomena into three kinds. These they termed the cosmic, acronych, and heliac risings and settings. The cosmic rising or setting ([Greek: kosmikos epitolae], or [Greek: dusis],) was the true one in the morning; the acronych ([Greek: akronychos][1]), _prima nox_, is evening, the beginning (one end) of the night, the true one in the evening; the heliac, ([Greek: haeliakos]) the apparent rising in the morning or setting in the evening. A star was said to rise or set cosmically, when it rose or set a...