Huges-Owens 341-3526

The 341 3526 rule was produced in Japan by Sun-Hemmi Ltd. from 1949 until 1972, to be commercialized in Canada by Hughes-Owens Ltd. This rule, as well as the Post 1447, is a clone of the Hemmi 40 RK. Fabricated with two bamboo strips riveted to a metallic strip, coated the front faces of these two strips and the slider with white plastic where scales were engraved. The glass cursor is mounted in a metallic frame. On the back face, covering the metallic strip, a table with rule settings for unit conversion, important math constants, and some trigonometric identities.

This is a Mannheim rule intended to be used as primer rule by students, or other slide rule beginning users. the scales on this rule are A [ B, CI, C ] D, K on the front face, and [S, L, T] on the slider's back.

Sun-Hemmi Ltd slide rules began to be commercialized in Canada by Hughes-Owens in 1914. sun-Hemmi produced it first Mannheim rule, Tamaya 4451, in 1932. I have not found a Hughes-Owens Catalog from those years to see if this Mannheim model was commercialized before the WWII.

According with the letters engraved on the back of the item in this collection, and the Hemmi production years reference table in the ISRM, this rule was manufactured on February 1968:

Click on the next links to see professional panoramic pictures of the 341 3526 Student Slide Rule:

https://www.sliderulemuseum.com/Hemmi/S291_Hemmi_Hughes-Owens_341-3526_Student.jpg