TitleCathedral galvanometer, Elliott Bros About this objectThis cathedral-style galvanometer was used to detect and measure small electric currents, which helped detect weak or interrupted signals, test line integrity and diagnose faults in the circuit – a crucial task in telegraphy to ensure reliable communication, especially on submarine cable routes.
Galvanometers evolved from early ‘multipliers’, functioning based on the principle that a magnetic needle is deflected by the presence of an electric current in a nearby conductor. Increasing the amount of turns in the coil over the needle could increase its sensitivity, making small currents measurable. ‘Multiplier’ was later renamed after Luigi Galvani, whose 18th-century experiments with electricity and muscle movement inspired the field of electrophysiology and early electrical science.
This object features an arched, cathedral-style casing made of varnished timber with brass fittings, which houses a suspended coil that responds to electromagnetic fields generated by a passing current. The back panel features four terminal screws, two for each coil, indicating that this is a twin-coil galvanometer. The inscription ‘R 42.9’ likely indicates the coil resistance. This device would have been used alongside a Wheatstone Bridge (such as Object 99.83 in the La Perouse Museum collection) to measure extremely low direct currents with precision. Galvanometers like this were critical to the operation and maintenance of long-distance telegraph lines, where even minute fluctuations in current could affect transmission quality.
Established in the early 19th century, Elliott Brothers (London) began as a maker of drawing instruments. By the mid-1800s, the company was manufacturing electrical instruments, and later amalgamating with telegraph and instrument makers Theiler & Co. In 1917, Elliott Brothers (London) became a limited company. The absence of ‘Ltd’ on the dial suggests the device predates that year. Object No.99.93CreatorElliott BrosInscriptions & marksFront: ELLIOTT BROs / LONDON
Back: R 428 / R 429 Place madeLondonSourceLa Perouse MuseumOn displayNoTypeMuseum objectsOrganisations (Detailed entries)La Perouse Museum (La Perouse, N.S.W.)ThemesScience and communication
