Vintage BEALL Steel Pipe Slide Rule Calculator 10x4 Cardboard – Spokane/Boise

Vintage BEALL Steel Pipe slide-rule calculator, likely mid-century promotional piece from Beall Pipe & Tank (Pacific Northwest steel pipe/tank supplier). Size: approx. 10" × 4" Material: cardboard with sliding inserts Cities shown: Spokane / Boise (and other branch locations) Condition: faded from age but completely legible; sliders move; no writing. Great for collectors of industrial tools, engineering ephemera, and slide-rule calculators. Displays well and still functions as a reference.