JENKIN’S “PATENT MAGNETIC COMPASS BEARING PROTRACTOR AND COMPASS COURSE FINDER
Stock Number: 9384
For sale, antique protractor designed for pre-correction of compass error. An uncommon instrument in its original mahogany box.
11/12 inches (29 cm) long
c.late 19th century
Country of manufacture
UK and Ireland
JENKIN’S “PATENT MAGNETIC COMPASS BEARING PROTRACTOR AND COMPASS COURSE FINDER,” English, late 19th century, unsigned. Made of plated brass with an 11-1/2″ (29 cm) long clampable brass index arm, this multipurpose navigational charting instrument has a divided square and calibrated clampable circle with compass headings and degree scale. We have seen an original instructional sheet and testimonials, indicating that the principal advantage of this instrument to the navigator is the ability to apply the compass error (variation and deviation combined) to “any Bearings he may wish to take before they are actually taken, and this entirely does away with the chance of applying the Error the wrong way, a not uncommon mistake.” A most uncommon instrument, very fine, with the original mahogany box.
Ask the Dealer
David and Yola Coffeen both have enjoyed academic careers, as planetary astronomer and as linguist/educator. But since 1982 (yes, 1982!) they have been full-time dealers in early scientific and medical instruments, under the name Tesseract. Selling primarily by catalogue (over 100 issued so far) they also have a web presence at www.etesseract.com, and can be contacted at [email protected]