CHEMICAL ENGINEERING SLIDE RULE
Stock Number: 7316
For sale, an interesting rule for multiple calculations, most particularly for chemical engineering. It is made of laminate over bamboo, and is 12-1/2 inches in length.
12-1/2 inches (32 cm)
Country of manufacture
CHEMICAL ENGINEERING SLIDE RULE, Japanese, c. 1960, signed “Hemmi, Japan, No. 257.” The 12-1/2″ (32 cm) long rule is made of laminate over bamboo, metal bound, and fitted with double-sided sliding glass cursor. The two sides of rule and slider are divided with a total of 23 scales, including gauge marks for determination of atomic and molecular weights, temperature, conversion scales, pressure unit conversions, molar / weight / volume fractions, adiabatic compression and expansion, etc. In addition there are the standard scales of multiplication, roots, logarithms, exponents, etc. The outfit is in near new condition, complete with instruction manual and leather case. The Hemmi Slide Rule Company was established in 1895 (first as Henmi Jirou & Co.) They became a major manufacturer of both standard and specialized slide rules, introducing the model 257 in 1954. But within 10 years the introduction of electronic calculators initiated the precipitous decline in slide rule manufacture, and the Hemmi company eventually turned to electronics.
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.