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

Eight various valves. .1) Matchlett Rectifying Valve Type ML-IE, 11.7 AMP@10v, oil immersion .2) Mullard TY2-125, Serial Number 4878./3 26UJ 5U4GB Miniwatt 980 .4) Electonic Comany New Jersey ELCGH-1/5 Collidge Tube, G.E./GMINNIWATT955 6x5GTscientific instrument, valves, mullard, rectyfying valve, electrons co, eimac, general electic, lamp, machlett laboratories inc., miniwatt

The Michelson Interferometer, sotred in a polished timber carry case. An optical isntrument, incorporating mirrors, lens, and adjusting mechanisms, all mounted on a heavy and solod cast metal base. Instruction manual available. scientific instrument, bellingham and stanley ltd, interferometer

This item was used at the Ballarat School of Mines during Physics lectures. Wave demonstration apparatus in a wooden frame for benchtop use. scientific instrument, wave demonstraton apparatus, ballarat school of mines, h.b. silberberg & co.

Two pan balance.scientific instrument, balance

Magnetometer set in a black storage box with hinged lid. Inside is lined with blue flet, wirh moulded recessed for all parts. The magnetometer incorporatethermomtetr and viewing windows for observing interally mounted mirror. Included also 3 pages of instructions in French. scientific instrument, magnetometer, andersson and sorensen

Dip circle apparatus contained in a glass-sided vertical wood cabinet, which can be rotated around a vertical axis through 360 degrees. Fully graduated circular scales and levelling screws in the base. Instructions for use available. scientific instrument, dip circle apparatus

A.C. Bridge MK 7A. A black instrument panel with controls, connectors and a 0-5- microAmpere DC indicator located on thetop face, and the electrical components located on the underside. No mounting frames, hence components exposed and vulnerable. scientific instrument, barlow and kelly, a.c. bridge

Black box with silver hinges and clasp, lined with purple. Spectroscope silver with black ends. In cardboard box with company labelLabel: Kaneko Scientific Co., Ltd. Tokyo Japanspectroscope, japan, scientific instrument

A complex instrument used to determine the pH factor of liquid samples, in this case, dyes. Without this instrument to measure the pH level of dyes before use, it would be impossible to ensure successful and repeatable results when dyeing wool.pH meter contained within dark wooden box, opened with two brass clasps. Contains dials, an electrode, glass bottle of potassium chloride and instructions for use on card inside lid.textile testing, dyeing, woollen mill, ph, scientific instument