Hyperbolic Match Output


Maker:ECKEL (The Eckel Co., USA)

Model:Engineer's Log Log (Circular Slide Rule)


Scales Front: || LL1, LL2, LL3, LL4, C || D, DI, A, K, L || Scales are printed on cursor

Scales Back: || SH1, SH2, TH, D, ST, S, T < 45°, T > 45° || Scales are printed on cursor

Gauge Marks:

Cursor Front:

Cursor Back:

Construction: Diameter about 8".


Source: Fahey

Information: This is the only known circular slide rule with hyperbolic scales that was manufactured and sold to the public. (See Appendix regarding, "The Everitt Complex Hyperbolic Slide Rule of 1924").