Maker's Name: 
4 × 4 × 5 cm

This geophone, or jug, is typical of those used in the 1960s search for oil in Australia.

It consists of a coil of wire suspended in a permanent magnet field. It was screwed on to a spike (absent) and stuck in the ground. Two wires were connected to terminals on a top attachment plate (absent).

A hole was drilled in the ground, and explosives (ANFO and initiator) and fuse lowered by wooden sticks connected by brass ferrules into the hole.

When the explosive was set off (shot), the ground vibrations were registered by a linear string of these geophones, usually 24, and recorded on magnetic tape, by pens on paper and/or recorded on film.

The tape had 28 channels, 24 data, one timing, one up-hole shot initiation record, one time break (start of recording), one spare.

Reflection or refraction from/by underground layers was recorded, for later processing, with corrections, of a successive series of shots on to photographic film, and then interpretation.