Summary
Telegraph key and relay. The key was used for the transmission of signals in the Morse electric telegraph system. The relay was part of part of the circuit involved in receiving signals coming in from the telegraph line.
To transmit signals the operator depressed a pivoted metal lever (the key) to complete an electric circuit and transmit current along the telegraph line. Releasing the key broke the circuit and cut off the current. Letters and numbers were represented by a sequence of short and long current pulses, transmitted according to a defined code. The most widely used code was generally known as "Morse code".
When receiving signals, the current pulses coming in from the telegraph line activated the relay. From the relay, the signals could pass to a register and be displayed as long and short marks on a paper tape, or could be interpreted by an operator listening to the sounds made by the receiving instrument.
With marks of the Victorian Telegraph Service, which operated the telegraph system in Victoria from 1854 to 1869. Used at Melbourne Observatory.
Significance
This telegraph key and relay is one of the few objects in the telegraph collection that was used by the Victorian Telegraph Service which functioned between 1854 and 1869.
More Information
-
Collection Names
-
Collecting Areas
-
Acquisition Information
Transfer from Melbourne Observatory, 1945
-
User
Victorian Telegraph Service, Melbourne, Greater Melbourne, Victoria, Australia, 1860s
-
User
Melbourne Observatory, South Yarra, Greater Melbourne, Victoria, Australia, 1860s-1870s
-
Inscriptions
The base of the unit is marked with the resitance (213 ohms) and with a crown over the letters 'V. T. S.' The key is stamped similarly with the number 1078.
-
Classification
-
Category
-
Discipline
-
Type of item
-
Exhibition Collection Management
275 mm (Length), 410 mm (Width), 120 mm (Height), 2 (Weight)
-
Overall Dimensions
275 mm (Length), 410 mm (Width), 120 mm (Height), 2 kg (Weight)
-
Dimensions
405 mm (Length), 255 mm (Width), 120 mm (Height)
Measurement From Conservation. Measuring Method: Maximum dimensions
-
Keywords
Electrical Relays, Morse Keys, Telegraph Equipment, Telegraphy