4-inch Mannheim with Magnifying Cursor
Frederick Post model 1441  [1936-40]

Hemmi model 32.
Appears in 1936 Catalog and Price Lists through 1941 and then reappears after WWII with a CI scale.

Top edge (slanted) : 0-4 inches
Bottom edge: 0-10cm
Back of slide: [S, L, T]
Back of rule: THE FREDERICK POST COMPANY  No. 1441

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

Same as Post model 1440 (Hemmi 30) except magnifying cursor.
Note that Post/Hemmi 4-inch slide rules did not have CI scales until after WWII.