Such alterations may be due to the writer or writers of the MS., called the scribe or scribes, or to some other person or persons (for there may be several) called correctors.
high, and fitted to receive and alter at pleasure the several magnet and soft iron correctors.
vertical magnets are used; (3) is partly corrected by the soft iron correctors of D; (2) and the remaining part of (3) cannot be conveniently corrected for more than one geographical position at a time.
With the deflector any inequality in the directive force can be detected, and hence the power of equalizing the forces by the usual soft iron and magnet correctors.
Airy's and Flinders's correctors form the basis of all compass correctors to this day.