Collection of pages from K&E catalogs for the

4135 & N4135 Power Computing Slide Rules


Catalog page from the 1913 catalog

The 4135 and N4135 Power computing slide rules were specially designed for power calculations that relate to steam engines.

The 4135 was offered between 1913 and 1921. It is a 7 inch duplex rule with two slides and no cursor.

In 1922 the N4135 replaced the original 4135 with a significantly different format. It is a 5 inch duplex rule similar to the 4088-1.

Catalog page from the 1930 catalog


The 4135 was first shown in the 1913 soft bound catalog that was released late in 1913. In 1922 the model number was changed to N4135 with a different frame style. The N4135 rule was last shown in the 1937 catalog.

Links to catalog pages for the 4135 and N4135 family of slide rules:

Scans: Scans of 4135s