- an instrument for measuring the angle of elevation of heavenly bodies, consisting of a calibrated staff with another shorter staff perpendicular to and sliding on it.
Origin of cross-staff
Examples from the Web for cross-staff
Historical Examples of cross-staff
The simplest and crudest form of measurer of which the record has been preserved is known as the cross-staff.
Even the navigators of the fifteenth century were aware of the deficiencies of the cross-staff and sought to improve upon it.
The vane of a cross-staff, made to slide along it by means of a square socket; it may be set to any of the graduations.The Sailor's Word-Book
William Henry Smyth
Iacobs staffean instrument formerly used for measuring the altitude of the sun; a cross-staff.The Fatal Dowry
Above, it has the small arc of the Davis quadrant with the sliding rod of the cross-staff below.Old-Time Nautical Instruments