Multichannel Earth Resistivity Measuring System

Geophysics Collection · Physics

Accession Number: 2015.ph.655

Description:

A large, red metal toolbox containing a complex electrical wiring system with various ports and outlets. Wiring appears to have been added at different times for new and adapted uses, and the entire system seems to have been hand-constructed. Some switches and outlets are labelled with vinyl labels, and most of the wires are given designated letters with sticker labels. Cables appear to be telephone or computer peripherals, with one large length of coaxial cable.

The inner lid of the toolbox contains two power sources connected to a small circuit board, attached to five different wires, one of which is severed (with the metal wiring exposed). The main part of the toolbox contains 16 identical ports for telephone cables, labelled “Line 1”, “Line 2”, “Voice”, and “Data”. A panel of switches is adjacent to the ports, with 16 larger metal switches and nine smaller switches. Each of the large switches is numbered 1 through 16, while the smaller switches are designated with letters from A through H.

The toolbox has three handles, one on each end and one on the top of the lid. Gray metal attachments are present on the left and right of the box, one of which appears to be a supplemental power source with four ports and a switch. The attachment on the bottom left corner of the front of the toolbox is a small, rectangular projection, holding a piece of cardboard held together with plastic strapping tape.

The attachment on the right side has one port and is smaller than the other two. There are splashes of blue paint on the front, top and inside of the toolbox. A small label on the front of the toolbox bears the name “Beach Industries Limited”. Two other stickers are present, one reading “Snap-On” and partially covered by the small rectangular attachment on the bottom left corner of the front of the box, the other a partially damaged “Apple Computer” sticker in the form of the classic “rainbow apple” logo on the left end above the supplemental power source. Stickers are also present on the top of the lid.

Primary Materials: Steel, Plastic, Rubber.

Markings:

Left side: “Apple Computer” decal (rainbow logo)
Power source labels: “RX COMP, 0, 6”

Front sticker: “Snap-On High Performance”
Front label: “Beach Industries Limited”, “Made in Canada”, other text illegible from fading

Contents: “Voice”, “Data”, “Line 1”, “Line 2” (repeated, on telephone jacks)
“Electrodes” – vinyl label on switches

Top of lid: Sticker with a small cartoon figure of a man in a kilt, sticker reading “Snap-On Tools”, sticker reading “Super Bright the lock never been picked!”

Dimensions (cm): Height = 25, Width = 32, Length = 75.

Function:

This instrument was developed to measure electrical resistivity across a grid of 256 electrodes placed in the ground. Its purpose was to produce ground resistivity surveys for archaeological purposes.

Condition:

Good: yellowed plastic and some damaged wires, peeling paint on inside and outside.

Manufacturer:

University of Toronto, Department of Physics, Geophysics Group

Date of Manufacture: c. 2000

Provenance:

This instrument was made by Roderick John Fisher in the laboratory of Dr. Gordon West. It was tested at the Fort York National Historic Site in Toronto, Ontario in an effort to locate buried structures as evidence of earlier housing.

It was acquired by the University of Toronto Scientific Instruments Collection on August 25th, 2014 from a storage room in the McLennan Physical Laboratory building.

Additional Information and References:

Fisher, Roderick John. (2000). Pole-Potential Mapping of Synthetic Arrays in Electrical Exploration (Doctoral dissertation). Toronto, ON: University of Toronto.

An audio interview with Gordon West (Jan 6, 2015) discusses this instrument.

  • Donated to UTSIC