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Frederick Post Co. No. 1447 (Made in USA)

• Type: Closed Body Enhanced Mannheim
• Size: 10 Inches
• Material: Pine and Ink.
• Scales:
  • Front: A [ B CI C ] D K
  • Back: [ S L T ]

Post normally went to Hemmi for their slide rules, but this was inconvenient between 1941 and 1945 due to Hemmi being owned by an enemy nation. But there was a war on and slide rules were in great demand. Post turned to a number of domestic manufacturers in the meanwhile.

This rule is nearly Identical to the Lawrence Engineering Service 250BT and was almost certainly made by Lawrence.

After the war concluded, Post could again buy rules from a closely-monitored Japan. See the postwar version of the 1447.