Hemmi-Post 1452, 1452P&W, 1444P
The Frederick Post 1452 family was manufactured since 1925 until 1961 in different countries. The early models in Germany and Japan (Frederick Post Co, began to commercialize the Sun Hemmi rules in 1931). There was a break during the WWII years with Japan. , during WWII in the United States and after WWII in Japan and in the United States.
These Mannheim models were commercialized in the United States by Frederick Post Company. During these years the 1452 family was fabricated with wood, bamboo covered with celluloid, and white plastic.
The plastic 1452P (10 in long) and the 1444P (5 in long) models were fabricated in the United States during the WWII years by Charles Bruning Company Inc. They had glass cursor with metallic frame. The scales on this rule are: inches A [ B, CI, C ] D, K centimetres in the front face, and [ S, L, T ] on the back of the slider. The 1452P had a Unit Conversion Table on the back face, while the pocket 1444P was blank
The 1452P rule is practically identical to the 1950's version of K&E 4053-3, but the Conversion Tables at the back of the 1452P is more complete and cursors are quite different, and in my personal opinion the 1452P is more aesthetic:
The 1452W model was fabricated in Japan by Sun Hemmi Inc. in the early 1960's. The materials used were the standard used by Sun Hemmi, plastic coated bamboo supported with a metallic plate. There is no difference in the scale set with the 1452P
There are no serial numbers or other engraved information on the 1452P and 1444P in this collection, but it seems that the 1452P specimen was fabricated between 1942-1945, the 1444P between 1942-1945, The 1452W has engraved the code RE, and according with the references at the ISRM indicates that this rule was fabricated in May 1967.
A skillful user can solve the next problems with a precision of two-three decimals:
SlideRulePractice-1.pdfNext is the Quick Reference for these models:
M69_Post_Mannheim_instr_1452P.pdfNote: Click on the next links to see professional panoramic pictures of the 1452 and 1444P models.
References.
Roos, Paul - Hume, Ted: Slide Rules of the Frederick Post Company. Journal of the Oughtred Society, Vol.9 No.2 Fall 2000. http://www.oughtred.org/jos/articles/V09.2_p37-46.pdf
Roos, Paul - Hume, Ted: Post Slide Rule Archive. Sphere Research Corporation: https://www.sphere.bc.ca/test/post.html An extensive classification of Frederick Post slide rules can be found in this web-page.
Roos, Paul - POST Slide Rule Cross Reference: Every slide rule sold by the Frederick Post Company of Chicago starting in 1903. http://srtco.us/PostCrossRef/Index.htm