Manufacturer: Keuffel and Esser
Country of Manufacture: U.S.A.
Type: Thacher 4012 Cylindrical (Type 3)
Number: 6406
Date of Manufacture: ~1940
Scales: (Front) 20 Axial Rib Segments (B and C scales)
Scales: (Back) Rotating Inner Cylinder (the A scale)
Number of Scales:  
Gauge Points:  
Slide Rule made from: Brass on a mahogany base with varnished paper mache scales
Cursor made from:  
Cursor Lines:  
Overall Length of Rule: 22 1/2"
Length of Scales: 18" long. Outer cylinder 6" diameter. Effective length of scales 30'
Width: Inner cylinder 4" in diameter
Acquired from: Jeff Marchant
Date: Feb 2002
Condition: Good
 Box 24" x 6 5/8" x 6 3/8". Good condition.
 Instructions. Good condition