4-inch Mannhiem with Flat Lens
Frederick Post model 1440  [1936-40]
Hughes-Owens model 1761
Hemmi model 30.

Appears in 1936 Catalog and Price Lists through 1940.

Top edge (slanted) : 0-4 inches
Bottom edge: 0-10cm
Back of slide: [S, L, T]
Back of rule: THE FREDERICK POST COMPANY  No. 1440
@SUN@ HEMMI  MADE IN JAPAN


This page is from the 1936 (18th Edition) Post Catalog 

Note that Post/Hemmi 4-inch slide rules did not have a CI scale before WWII.