5-inch Mannheim Multiphase
Frederick Post model 1438  [1936-40]

Hemmi model 36.
Appears in 1936 Catalog and Price Lists through 1940.
 

Top Edge: Blank
Bottom Edge: Blank 
Back: 0-15 cm and 0-5 inch scales.
Paper Table
Back of slide: [S, L, T]

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

Similar to Post model 1437 except with CI scale and scales are 2.5 cm longer.