Frederick Post models 1431-34  [1910]
 
 
.Frederick Post Model 1434 10-inch "Engineer's" Slide Rule

Specimens of models 1431, 1432, and 1433 not available.
 
Model 1431 appears to be same as Dennert & Pape model 5 (1914-19 D&P Catalogs)  Note "Dennert & Pape" visible in catalog illustration.

Model 1432 appears to be same as Dennert & Pape model 6 (1914-19 D&P Catalogs) 

Model 1433 appears to be same as Dennert & Pape model 7 (1914-19 D&P Catalogs) 

Model 1434  appears to be same as Dennert & Pape model 9 Rietz  (1914-19 D&P Catalogs) 

"Adjustable" means the rule uses the D&P DRGM 192052 friction adjusting mechanism.