scale interpolators
Date: 1960-1980
Inventory Number: 2004-1-0362
Classification: Scale [Distance]
Dimensions:each piece: 0.1 × 7.7 × 16.3 cm (1/16 × 3 1/16 × 6 7/16 in.)
in folder: 0.2 × 9.5 × 16.7 cm (1/16 × 3 3/4 × 6 9/16 in.)
Accessories: blue storage envelope; instructions (with instrument)
DescriptionSet of two clear plastic cards. Printed along the top edge of the card is a scale in inches, graduated into 50ths (0 to 1 inch), 10ths (1 to 2 inches), 12ths (2 to 3 inches), 16ths (3 to 4 inches), 24ths (4 to 5 inches), and 32nds (5 to 6 inches). Along the bottom edge of the card is a scale in centimeters, graduated into tenths.
In the top right corner of the card is a one square-inch grid, divided into boxes one-tenth of an inch on each side. In the bottom left corner of the card is a one square-centimeter grid, divided into boxes one-tenth of a centimeter on each side.
A semicircular protractor is printed in red in the center of the left edge of the card. It is marked for ten-degree increments in a counterclockwise direction.
Within a triangle in the bottom right half of the card are a series of lines labeled "LOG INTERPOLATOR". Each line begins in the bottom left corner of the triangle, and extends to its right edge. Along the right edge these lines are marked with numbers ranging from 1 to 10. The bottom edge of the triangle is labeled "BASE LINE".
A similar triangle is printed upside-down in the upper left half of the card and labeled "LINEAR INTERPOLATOR". The lines ending at its right edge arm marked with numbers ranging from 0 to 1; its bottom edge is also labeled "BASE LINE".
The cards, along with instructions for their use, are stored in a blue paper envelope. The envelope has two brass-reinforced holes punched near its left edge, for insertion into a three-ring notebook. Information on the Bendix Corporation is printed on the back of the envelope.