There is a common received opinion that if the lodestone be rubbed over with garlick or onions that it will obstruct the virtue thereof; or if a knife being touched upon the lodestone and afterwards cut an onion or garlick it will immediately lose its virtue. This conceit hath also been countenanced by the Ancients, but if you are pleased to make a trial you will find it to be but a mere fallacy. It is also false that the diamond doth hinder the virtue of it while it is near it. (John Seller, Practical Navigation, 1694)
FINE BRASS-BOUND LODESTONE, c. late 17th century, measuring 4-1/4″ (11 cm) tall including suspension ring, the ends scratch-labeled “N” and “S.” This dramatic lodestone has a naturally magnetic irregular “chunk” of magnetite, clearly visible within the two horizontal brass straps which conform to the shape of the stone. Mounted to the upper strap is a U-shaped strap with suspension ring, acting as a sort of “gimbal” mounting permitting the stone to swivel in two directions and thus find its own vertical. There are iron pole pieces, again well-shaped to conform to the natural shape of the stone, in order to concentrate the field strength. Condition is very fine, noting a bit of oxidation to the iron. It retains a low degree of magnetization.
This is a handsome lodestone, “powerful” in making very visible the combination of nature’s and man¹s inventiveness. Rarely is the naturally shaped stone so apparent within the metal casing. It may be compared with an encapsulated example (Tesseract Catalogue 100 Item 77), and with a large partially hand-shaped one (97/30).
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 firstname.lastname@example.org.