Slide rules HOME page COLLECTION 5" RULES
Make Keuffel and Esser, USA
Model 4161-1

1. Has a rather unusual set of scales. There is no B scale but there is an A scale on the lower front face of the stock. There are also CF and DF scales.
2. Has trig scales on the back of the slide which has to be turned over to use them - though there is a repeated C scale which can facilitate some calculations.

Front view
0514-ke4161-1-01.jpg (12576 bytes)
Detail - left front view
0514-ke4161-1-02.jpg (17007 bytes)
Detail - trig scales on back of rule
0514-ke4161-1-03.jpg (14047 bytes)
Manufacturing date c 1960. My estimate.
Length 5"
Material Plastic
Scales K, DF [ CF, L, CI, C/ T, ST, S, C] D, A
Cursor Plastic
Hair lines None
Documentation None
Condition Complete in leather pouch.