This item was probably acquired for, and used by, participants in telegraphy at the Ballarat School of Mines courses between 1873 and 1893.An electromagnetic relay device on a brass base plate, and mounted onto a wood base. It is covered by a removable wood-framed glass sided cage. The item has four terminal posts and an adjustable conductor mechanism.ballarat school of mines, telegraphy, relay device, telegraph coding

Probably acquired for use in Telegraphy courses run at the Ballarat SChool of Mines between 1875 and 1893. Telegraph relays amplified electrical signals in a telegraph line. Telegraph messages traveled as a series of electrical pulses through a wire from a transmitter to a receiver. Short pulses made a dot, slightly longer pulses a dash. The pulses faded in strength as they traveled through the wire, to the point where the incoming signal was too weak to directly operate a receiving sounder or register. A relay detected a weak signal and used a battery to strengthen the signal so that the receiver would operate. This relay was made by the firm of Charles T. and John N. Chester, two brothers who successfully partnered in New York City. Charles (1826-1880) founded the firm and provided the expert telegraphy knowledge while John (1820-1871) kept the books and managed the business operations.(http://americanhistory.si.edu/collections/search/object/nmah_706518, accessed 25/01/2018)Electromagnetic relay device used in telegraphy. The working parts mounted on a brass plate, attached to a wood base. Equipped with four terminal posts. Adjustable contactor mechanism. This electromagnetic Relay Device was used in Telegraphy at the Ballarat School of Mines. After a special meeting of the Ballarat SChool of Mines Council in 1874, a decision was made to offer instruction in Telegraphy, a subject not directly related to mining. Telegraphy was taught by W.P. Bechervaise, postmaster at Ballarat. On 07 October 1874 the Ballarat Courier correspondent reprted on Telegraphic training: "... these classes ... are a snare and a delusion, as there is scarcely the remotest chance of obtaining employment when the examination has been passed."scientific instrument, telegraph relayer, telegraphy relay device, telegraphy

Dr Nicholas Opie, a Forest Hill biomedical engineering researcher, is involved in developing a stentrode to be implanted in the human brain to record and relay brain signals to different devices.opie, nicholas dr.

Yields information about the reconstruction of the curve on the Mt Pleasant line at Stones Corner.Negative and Digital images of the Wal Jack Ballarat Negative file of the relay of the outer rail at Stones Corner on the Mt Pleasant line. Shows removed rails and methodology of the work. Photo taken at 1220 as shown on the clock - all workers at lunch. In the view are the Listers COR service station, the Inspector chatting with a person, the Ballarat East Post Office and the Stones retail store. The first welding truck (cloth covered roof) with a wandering lead device. See Reg Item 7740 for a photo of similar work at Main and Barkly St.trams, tramways, stones corner, trackwork, track repairs, main road, victoria st, mt pleasant, inspectors, welding

Black and White PhotographAccompanying sheet reads, " 'Post 35' shows the scene from the foot bridge. The signalman is giving the staff to the driver of a dog box suburban train, from Bayswater because there is a train probably on arrival Croydon on the Croydon line. The right hand arm of the bracket is off for Bayswater. Post 35 at that time was a prefab structure which replaced the signal posts knocked down on 22/6/1945. The red brick building bottom right corner is the relay room which included devices which would probably have prevented the June 1945 accident".