"Electrical Engineer's Universal Duplex Slide Rule With Patent
Vector Scale, Gudermanian Scale and Log Log Scales"
slide rule
slide rule
Click to view 300 dpi image.

Virtual slide rule available.
Serial No.none
Date Codenone
Scale length25 cm
Overall length32.0 cm
Width4.0 cm
Body/Slide materialsPlastic on Bamboo
Post materialsMetal
Cursor materialsMetal / Glass
Scales L K A [B CI C] D T Gθ
θ Rθ P [Q Q' C] LL3 LL2 LL1
AccessoriesBlack cardboard case; repaired with electrical tape
NotesPatent covering special scales
Hemmi manual fragment covering trig and hyperbolic functions
JOS article about Hemmi trig and hyperbolic scales
Tag No.SH-153