K&E 4133 Family of Slide Rules


Scale sets :

Scale set #1 (1913-1922) for the 4133:

4133 --- 8" Roy Lance Electrical Slide Rule. No serial number. Early metal framed glass cursor with three hairlines.

Scale set #2 (1925-1936) for the N4133:

N4133 --- 8" Roy Lance Electrical Slide Rule. Serial number 155828. Replacement cursor with one hairline.


Scale set #3 (1936-1949) for the N4133: