Collection of pages from K&E catalogs for Log Log Duplex Decitrig

Demonstration Slide Rules


Catalog page from the 1962 catalog

K&E produced large demonstration versions of several of the most popular models. K&E model N105 is a 8 foot version of the 4081-3. It was intended to hang on a wall or frame for use in classrooms.

The following model numbers are part of the N105 Demonstration Slide Rule family:

On each of the catalog pages there is a note that the scale set of the N105 tracks the scale changes that happened between 1952 an 1956. This would indicate that there are rules out in the field with three different scale sets.


The model N105 was first shown in the 1952 Educational Products Catalog. In 1962 the model number was converted to 68 1923. The 68 1923 was last shown in the 1967 catalog. The following is a brief history of the N105 family of slide rules as is told in the K&E catalogs that are available at this time. Exact timing is not possible because of the time between catalogs.

Links to catalog pages for the N105 family of slide rules: