A measurement or reading taken right back towards a place of known height, used to calculate the height associated with theodolite.
A measurement of a previously shot point, always set the direction to zero when occupying a place.
The reading associated with the leveling staff in its unchanged place once the leveling instrument is taken fully to a position; a sight directed backwards to a station previously occupied. Cf. foresight, n., 3.
In surveying, the reading of a leveling-rod, taken whenever looking back to a station which was passed. All the readings are known as foresights.