RADIAC SLIDE RULE, FOR NUCLEAR FISSION PRODUCTS, English, mid-20th century, 11-3/4″ (30 cm) white plastic with two double-sided slides plus cursor, excellent and fascinating. $595.
MINIATURE, probably American, 2nd quarter 20th century, stamped “Buckeye Lamp Division, Cleveland, Ohio,” 4-1/2″ (11 cm) long plastic over wood, double-sided slide plus cursor, logarithmic and trigonometric scales plus ruler, fine. $120.
RICHMOND’S IMPROVED MILK SCALE, English, c. 1915, signed “Daisy Supply Co., Ltd., Park Royal, London, N.W. 10,” 12-1/2″ (32 cm) long, brass-bound boxwood, scales of Lactodensimeter Reading, Specific Gravity, Temp., Fat, and Total Solids, fine with one chip, rare. $395.
COMBINED SLIDE RULE AND RULERS, Japanese, 1961, so dated and signed “Scientific Instruments Co.,” Model 1050, 11-5/8″ (30 cm) long, plastic laminate over bamboo, double slide, cursor, table to reverse, original leather case, excellent. $275.
DICAS HYDROMETRY RULE, English, c. 1815, signed “Dicas Patent Improv¹d by Gill & Co. London,” 7-3/8″ (19 cm), ivory, slider and scales both sides, Water, Alcohol, Proof, etc., very fine with slide warping. Invented by John Dicas in 1780. $495.
UNUSUAL VINTNER’S SLIDE RULE. sold
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.