22728311911 Encyclopædia Britannica, Volume 7 — Culmination

CULMINATION (from Lat. culmen, summit), the attainment of the highest point. In astronomy the term is given to the passage of a heavenly body over the meridian of a place. Two culminations take place in the course of the day, one above and the other below the pole. The first is called the upper, the second the lower. Either or both may occur below the horizon and therefore be invisible.