Usage/History: This box would be used as a standard
resistance in laboratory work in schools. Resistance values are
adjusted by removing the brass pegs. The box is constructed with
the pegs in parallel with precision wound resistance coils-with
the peg in place the current flows through the peg (approx. 0
ohms), when removed the current flows through the resistor.
Some contemporary/early descriptions of the resistance box
and its use are provided below:
Resistance
Boxes Kimball, Arthur Lalane, A College Text-Book of Physics
(1923)
Description: The instrument is contained in a 8x4x3
3/4h" birch? box stained at one time to look like mahogany.
The top is of hard rubber with raised brass-work which has been
nickel plated on top, and apparently stained black on the sides.
The binding posts are nickel-plated brass with knurled nuts held
on by the screw heads. Screws and brasswork are also nickel plated("white")
tarnished to black. The resistance value is adjusted by inserting
plugs (tapered brass with black hard rubber handles) into holes
connecting the brass lugs on the top surface of the case. The
total resistance of the box is 1,110 ohms divided as follows:
1, 2, 3, 4, 10, 20, 30, 40, 100, 200, 300, & 400. The resistance
values are all white filled. There is an oval brass tag on the
bottom corner of the box beneath the rear binding post stamped:
HUMBOLDT S-T-C / 2112. There is a Welch decal in the center of
the opposite panel of the box.
