Electrical Horology Group
Welcome to the home page of the Electrical Horology Group, a specialist group within the AHS.
The Electrical Horology Group has been in existence since 1970 and has over 150 members worldwide.
EHG members share an interest in all electrical horology, from the early beginnings in the 19th century right up to relatively modern quartz and atomic clocks. The diversity of approach in applying electrical power to winding or maintaining a clock is immense, and the ingenuity of solutions to the problems encountered is fascinating.
Meetings are held approximately four times a year, usually on a Saturday in March/April, June, September and November. A variety of venues is used; please check Antiquarian Horology or this page for the latest programme information. Meetings may involve formal lectures, short talks, visits to places of horological interest, exhibitions, visits to private collections, and so forth.
The Annual General Meeting is held in November and is often combined with a special lecture given by a guest speaker.
The Group publishes technical papers from time to time on electrical horology matters that may not have a wide enough appeal for inclusion in the Journal (see the list of published papers at the bottom of this page). These papers are available here to AHS members as part of the searchable digital archive. New papers are dependent on members providing the material for publication. Over ninety such papers have been published so far.
Famous names in electrical horology
Personalities (listed chronologically)
Sir Francis Ronalds 1788-1873
Inventor of the Electrostatic Clock in 1814.
Alexander Bain 1811-1877
The "Father of electrical horology". He patented the first practical electromagnetically impelled clock in 1841.
Matthaus Hipp 1813-1893
Inventor of the Hipp Toggle in 1842 - a device attached to a pendulum or balance wheel that senses when the arc of swing reduces to a given point, and then closes an electrical contact to electromagnetically impel the pendulum or balance.
Frank Hope-Jones 1867-1950
Patented the best known, and arguably the most accurate, gravity impelled pendulum master clock in 1908, the Synchronome.
Henry Ellis Warren 1872-1957
Devised the first synchronous (A.C. mains powered) clock in 1918.
William Hamilton Shortt 1881–1971
Patented a highly accurate, electromagnetically impelled, free pendulum regulator clock in 1921. The clock operated in a vacuum chamber, and its accuracy was only superseded by the arrival of the Atomic clock.
Warren A. Marrison 1896–1980
Invented the quartz crystal controlled clock in 1927.
Louis Essen F.R.S. 1908-1997
Invented the Caesium Atomic clock in 1955.
Companies and Trade Names (listed alphabetically)
The company set up in France by Léon Hatot (1883-1953) made clocks under this trademark (a contraction of his own name) from 1919 . In the 1950's Hatot's company developed and patented the world's first transistorised electric clock.
The trade name of electromagnetic pendulum clocks marketed by a company set up in France by M. Favre-Bulle. Designed in France, they were given British patents in 1922. Production continued until stopped by the Second World War, with around 300,000 units made.
A very successful early electromagnetic clock manufactured between 1904 and 1914. The main feature was a very large balance wheel several inches in diameter. Around 10,000 clocks were made.
Gents of Leicester
A very successful company run by Messers Parsons and Ball manufacturing sturdy electrical Master Clocks from 1904 to the 1970s.
Hamilton Watch Co.
An American company which produced the first electrically maintained wrist watch in 1957, after 10 years research.
The trade name of Smiths English Clocks Ltd in Cricklewood, London. The company produced many thousands of electric clocks, both A.C. mains powered and battery powered during the middle years of the 20th century.
Started in 1895, this is the company name of Frank Hope-Jones. The company produced very accurate electric Master Clocks that were capable of driving many slave clocks around a factory or office building in perfect synchronism.
The trade mark of the Warren Clock Company in America and applied to synchronous clocks (A.C. mains powered). The name literally means "time from a distance".
These are just a few of the more significant milestones in the development of electrical horology.
First practical electromagnetic clock, by Alexander Bain.
Distribution of time to public clocks, by Magnetic Telegraph Co, Glasgow.
Electric motor to wind clock spring, by Chester H. Ponds, (USA).
Eureka, first successful balance wheel electric clock, by T. B. Powers (Patented by Kutnow Bros).
Synchronous electric clock invented (A.C. mains powered), by Henry Ellis Warren (USA).
Quartz crystal controlled clock invented (experimental design), by Warren A. Marrison.
Synclock: one of the first domestic synchronous clocks for the UK (Warren motor, A.C. mains powered), by Everett, Edgcumbe & Co.
Speaking clock: the first accurate fully automatic service, Paris.
Transistor first used to electronically maintain a pendulum, by Leon Hâtot (France).
Caesium atomic clock, by Louis Essen.
Wrist watch with electrical contacts operated directly by balance wheel produced commercially, by Hamilton Watch Co (US).
Accutron watch using an electronically maintained tuning fork as timing element, by Bulova.
First LED display on a wrist watch.
First LCD display on a wrist watch.
First mass produced domestic quartz clock, by Staiger in Germany.
EHG Technical Papers
The Electrical Horology Group of the AHS has published a number of technical papers over the years, covering a wide range of electrical horology topics.
These papers are now available here to members of the society as part of the searchable digital archive.
The complete list of such papers shown below indicates the depth and breadth of information available to members.
- List of articles on Electrical Horology from "Horology" and "The American Horologist & Jeweller"
- List of works on Electrical Horology
- List of works on Electrical Horology from "Practical Watch & Clockmaker
- List of articles on Electrical Horology from "Model Engineer"
- Electricity for the Antiquarian Horologist - An introduction in 5 parts
- A Chronoscopic Conundrum
- A Pendulum Electric Timepiece ca 1845 made by Alexander Bain of Edinburgh
- Spark Prevention
- The Magnetic Escapement
- Electric Clocks - controlling the current
- An Electrically Maintained Precision Pendulum Clock
- Magneta Master Clock - Translation from the French
- The Evolution of Timeswitches
- The "Brox" Electric Pendulum
- Digital Calendar Clock
- Electronics in Timekeeping
- Time Balls in and Around Charing Cross
- Bright's Perpetual Motion Electric Clock
- Quartz clocks and Atomic Time
- Eureka Clock Survey
- Rugby 60kHz Broadcast
- The Synchronome Master Clock - Adjustment and Setting to Work
- Electric Clocks Acquired by the Science Museum in 1978
- Breguet's Electric Clock
- Replacing a Bulle Clock Suspension, March 1980
- The Development of Batteries for Electric Clocks and Watches
- Electrical Horology Group - The First Ten Years
- The ATO Electric Clock
- An Early Electric Clock System
- The Role of Electrical Horology in the Development of the Quartz Clock
- Master Clock - Quartz Controlled Time Transmitter
- The "Chronopher" Master Clock System
- The Construction and Early Development of the Talking Clock
- A Proposal for a Time Ball at Boston, USA
- List of Major Electric Clock Literature available from The Franklin Institute Library, USA
- The "Synchronome" Astronomical Regulator>
- Improvements to Astronomical Clocks
- Stored Energy Power Supply for Synchronome Impulse Systems
- Adjustments to the English Clock Systems Master and Slave Clocks
- ITR/IBM Supervised Time System - Principle of Operation
- Hints for Servicing Pulsynetic Clocks
- Electromagnetic Clock Literature of the 19th Century
- Telephone Manufacturing Company Ltd. High Movement Impulse Transmitter
- Electric Clocks in the Science Museum Reserve Collection
- The Greenwich Mean Time System
- Time in Broadcasting
- The Latest Developments in Quartz Crystal Oscillators
- The Telephone Rentals Uniselector Chronogram
- The Electric Clock Systems of the London Underground
- An Earth Cell Experiment
- National Time Standards
- Almost Perpetual Motion - The Amazing Clinker Pendulum Clock
- 100 Years of the Domestic Electric Clock
- (The Bulle Clock - Practical Manual) Available as a book from the AHS
- The Fedchenko Isochronous Pendulum Suspension Spring
- Catalogue of Exhibition of Electrical Clocks Working on the Hipp Toggle Principle
- Matthaus Hipp of Reutlingen
- Smiths - An Overview of Their Activities in Electrical Horology
- Warren's Synchronous Clocks
- Ffolliott Gray's Invention "The Duo Electric Clock"
- Siemens & Halske Electric Clocks 1847-1945
- Post Office Clock Survey
- "Clocks Magazine" - Electrical Horology Index
- Gillett & Johnston Master Electric Clock - Setting up and servicing
- Rabe Bros. of Hanau - Torsion Pendulum Clocks
- The Beginning of the Liquid Crystal Watch
- Pul-Syn-Etic clocks, Installation, Maintenance and Repair (Revised)
67. Pul-Syn-Etic Clocks, Supplement 1
67. Pul-Syn-Etic Clocks, Supplement 2
- English Clock Systems Ltd 1-Second Master Clock
- Gent Fig.C53 Strike Controller
- 100 Years of Paul Schroder of Stuttgart 1902-2002
- The Quartz Revolution
- Master Clocks Designed & Manufactured By Gent Ltd - 1898 to 1980
- A Celebration of the Centenary of the Eureka Clock Patent
- The Lowne Electric Clock Company - History & Servicing the Master Clocks
- Servicing Procedures & Catalogue Details for the TMC 'SPB' Half Second Master Clock
- Bulle: A Study into the Effectiveness of the Isochronous Spring.
- An Approximate Expression for the Effect of the Bulle Isochronal Spring
- Frank Holden – the Man and his Clocks
- P A Bentley - The Man and his Clocks
- Recollections of 40 years of the Electrical Horology Group
- A Game of Numbers - some observation on serial numbers
- English Clock Systems Ltd - Revisited
- Telephone Rentals and their activities in electric clocks
- Battery Insertion Movements DVD
- Searching Patents
- Stanley John Wise - The Author and His Electric Clocks
- An earth cell investigation
- Index of electrcal items in Clocks Magazine - Paper No 63 update
- Tayco clocks
- The ‘Wallace and Tiernan’ Electric Clock
- The Forestville ‘Eureka’ Electric Clock
- Gent DAC Chronometer
- Gent Survey - The Results
- Vitascope clocks
- ITR Electronic Master Clocks Models M23, M24 & M27