ProvenanceThese relays were used from 1860-1962. This instrument was presented to the Art Gallery of South and later transferred to the History Trust of South Australia in 1984.SignificanceThe Overland Telegraph changed the way Australians communicated with the rest of the world and each other. The 3178 kilometre line was built in less than two years and joined on 22 August 1872. It linked Australia to an undersea cable from Indonesia that came ashore at Port Darwin and made communication between Australia and the rest of the world possible in hours rather than weeks or months. This telegraph relay instrument is part of the Historical Relics Collection. This instrument was used in telegraph communication in South Australia in the 19th and 20th centuries. The telegraph relay instrument was used to receive electric signals from distant telegraph stations. These signals controlled a sounder, which made the signal audible to a telegraphist. The large horizontal electromagnets have coils of insulated copper wire wound onto a soft iron core. These operate the vertically mounted armature to move between electrical contacts. The electrical resistance varies from 150-250 ohms in various makes.DescriptionA telegraph relay instrument placed on a rectangular wooden base of three layers of wood. On this base is a rectangular sheet of brass to which the mechanism is screwed from the underside. On the left hand side are four cylindrical parts, each with a hole through the side centre and a small ‘hat’. Underneath each cylinder is wire set into the wood. On the surface there are two horizontal cylinders, connected by springs, wheels, rods, and plates. A small plate fixed beneath the cylinder reads ‘H WASSERLEN / BERLIN’.Creator (person)H WasserlenKeywordscolonisationDate of Creationc1860MaterialWood - unspecified
|Metal - brass DimensionHeight: 100
Width: 225
Depth: 130
Unit (Lengths): mm
|Type: total Accession NumberHT 1986.0467