alb3816576

Cross-staff, Navigational Instrument

The term cross-staff, also Jacob's staff, ballastella, balestilha, or fore-staff is used to refer to several things. The two most frequent uses are: in astronomy and navigation for a simple device to measure angles, and in surveying for a vertical rod that penetrates the ground and supports a compass or other instrument. The cross-staff consisted of a long staff with a perpendicular vane which slides back and forth upon it. The staff is marked with graduated measurements - calculated by trigonometry. The angles can then be measured by holding it so the ends of the vane are level with the points to be measured. Early in the sixteenth century it was already in use as a seaman's navigational instrument.

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Title: Cross-staff, Navigational Instrument

Caption: The term cross-staff, also Jacob's staff, ballastella, balestilha, or fore-staff is used to refer to several things. The two most frequent uses are: in astronomy and navigation for a simple device to measure angles, and in surveying for a vertical rod that penetrates the ground and supports a compass or other instrument. The cross-staff consisted of a long staff with a perpendicular vane which slides back and forth upon it. The staff is marked with graduated measurements - calculated by trigonometry. The angles can then be measured by holding it so the ends of the vane are level with the points to be measured. Early in the sixteenth century it was already in use as a seaman's navigational instrument.

Category: Science: History

Credit: Album / Science Source / New York Public Library

Releases: ? Model Release: No - ? Property Release: No
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Image size: 4800 × 3137 px | 43.1 MB

Print size: 40.6 × 26.6 cm | 1889.8 × 1235.0 in (300 dpi)

Keywords: 16 16TH XVI XVITH SIXTEENTH CENTURY • 16 CENTURY • 16TH CENTURY • 16TH • ART • ARTWORK • BALESTILHA • BALLASTELLA • BW • CELEBRITIES • CELEBRITY • CROSS STAFF • CROSS-STAFF • DEVICE • DIAGRAM • DRAWING • FAMOUS PEOPLE • FAMOUS • FORE STAFF • FORE-STAFF • HISTORIC • HISTORICAL • HISTORY • ILLUSTRATION • ILLUSTRATIONS • ILUSTRATION • IMPORTANT • INSTRUMENT • JACOB STAFF • JACOB'S STAFF • MARITIME • MEASUREMENT • MEASURING • NAUTICAL • NAVIGATION • NAVIGATIONAL • NAVIGATORS • NOTABLE • PERPENDICULAR VANE • SCIENCE • SCIENCE: HISTORY • SLIDING VANE • TOOL • WELL-KNOWN • WHITE BACKGROUND • WOODBLOCK PRINT • WOODBLOCK • WOODCARVING • WOODCUT • XVI CENTURY • XYLOGRAPHY