Manufacturer: Gerber Scientific Instrument Company
Country of Manufacture: U.S.A.
Type: Variable Scale TP007100B
Date of Manufacture:  
Scales: (Front) R1, I, L10
Scales: (Back)  
Number of Scales: 3
Gauge Points:  
Slide Rule made from: Aluminium
Cursor made from:  
Cursor Lines:  
Overall Length of Rule: 30.3 cm
Length of Scales: 23.5 cm
Width: 3.7 cm
Depth: 1.3 cm
Weight: 122 gms
Acquired from: Debora K
Date: May 2002
Condition: Good
 Leather Case.  Good Condition
The heart of the Variable Scale is a high precision triangular spring 
whose coils act as calibrating lines. When extended, all coils are 
equally spaced. A second spring carries numerical markings for each 
10th coil of the triangular spring.

Easy to use, the Variable Scale makes computations directly -- without
conversion -- on graphs, curves and recordings. Expandable for any ratio,
any setting, it is used on graphical work where reading, plotting and
interpolating are required.

The use extends the Variable Scale's springs by sliding a hairline over 
three fixed, engraved scales: 1) an Inch scale that indicates the number 
of inches extended; 2) a Reciprocal scale that identifies the number of 
coils per inch; and 3) a Logarithmic scale that indicates the logarithm 
of the extension. Each scale, in combination with the spring, solves a 
group of common problems.