Hyperbolic Match Output

Number:79a

Maker:PICKETT & ECKEL (USA)

Model: 4-T Dual-Base Log Log Reciprocal Scale (Vector Hyperbolic)

PHOTO

Scales Front:||Three cube root scales ³√, DF|| CF, T&T, ST, S&S, CI, C || D, DI, Two sqrt scales √ ||

Scales Back: || LL₁&LL₁, LL₂&LL₂, DF || CF, Th, Sh&Sh, L, CI, C || D, LL₃&LL₃, LL₄&LL₄ ||

Gauge Marks: π is on C, D, CF, DF, CF/M, DF/M, CI, DI, CIF ; R and π/4 are on C & D; marks 1° , ' and " are on ST.

Cursor Front:

Cursor Back:

Construction: 25 cm.; White film over Aluminum, Cursor is not framed, Adjustable metal brackets.

Date:

Source: Herman's Archive

Information: Same rule but different colors as Model 4-ES Dual-Base Log Log Reciprocal Scale (Vector Hyperbolic) which has a yellow plastic film over Aluminum.