taken as known

The distance from an observer’s eye of an object seen would be specified as soon as it was ascertained that a rod, straight to the eye and of length taken as known, could be given the direction of the line of vision, and had to be moved along it a certain number of times through lengths equal to its own in order to reach the object from the eye.

The Choephori, like the plays of �schylus generally, consists of scenes from a story taken as known.

In astronomy, as in analytical geometry, the position of a point is defined by stating its distance and its direction from a point of reference taken as known.

The unknown is taken as known, and all the rest is deduced from it.

It is thus fairly certain that no large error can have been made in the determination of the position of the Endurance at any time during the drift, and her course can be taken as known with greater certainty than is usually the case in a voyage of such length.