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. These papers are available to Group members. New papers are dependent on members providing the material for publication. 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 The clock operated in a vacuum chamber, and its accuracy was only superseded by the arrival of the Atomic clock.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)

ATO 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.
Bulle 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.
Eureka 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.
Smiths Sectric 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.
Synchronome 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.
Telechron 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".

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These are just a few of the more significant milestones in the development of electrical horology.

1840 First practical electromagnetic clock, by Alexander Bain.
1864 Distribution of time to public clocks, by Magnetic Telegraph Co, Glasgow.
1881 Electric motor to wind clock spring, by Chester H. Ponds, (USA).
1906 Eureka, first successful balance wheel electric clock, by T. B. Powers (Patented by Kutnow Bros).
1918 Synchronous electric clock invented (A.C. mains powered), by Henry Ellis Warren (USA).
1927 Quartz crystal controlled clock invented (experimental design), by Warren A. Marrison.
1931 Synclock: one of the first domestic synchronous clocks for the UK (Warren motor, A.C. mains powered), by Everett, Edgcumbe & Co.
1933 Speaking clock: the first accurate fully automatic service, Paris.
1953 Transistor first used to electronically maintain a pendulum, by Leon Hâtot (France).
1955 Caesium atomic clock, by Louis Essen.
1957 Wrist watch with electrical contacts operated directly by balance wheel produced commercially, by Hamilton Watch Co (US).
1959 Accutron watch using an electronically maintained tuning fork as timing element, by Bulova.
1970 First LED display on a wrist watch.
1971 First LCD display on a wrist watch.
1972 First mass produced domestic quartz clock, by Staiger in Germany.

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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 available to members of the society on request only.

The complete list of such papers shown below indicates the depth and breadth of information available to members.

1 List of articles on Electrical Horology from "Horology" and "The American Horologist & Jeweller"
2 List of works on Electrical Horology
3 List of works on Electrical Horology from "Practical Watch & Clockmaker"
4 List of articles on Electrical Horology from "Model Engineer"
5 Electricity for the Antiquarian Horologist - An introduction in 5 parts
6 A Chronoscopic Conundrum
7 A Pendulum Electric Timepiece ca 1845 made by Alexander Bain of Edinburgh
8 Spark Prevention
9 The Magnetic Escapement
10 Electric Clocks - controlling the current
11 An Electrically Maintained Precision Pendulum Clock
12 Magneta Master Clock - Translation from the French
13 The Evolution of Timeswitches
14 The "Brox" Electric Pendulum
15 Digital Calendar Clock
16 Electronics in Timekeeping
17 Time Balls in and Around Charing Cross
18 Bright's Perpetual Motion Electric Clock
19 Quartz clocks and Atomic Time
20 Eureka Clock Survey
21 Rugby 60kHz Broadcast
22 The Synchronome Master Clock - Adjustment and Setting to Work
23 Electric Clocks Acquired by the Science Museum in 1978
24 Breguet's Electric Clock
25 Replacing a Bulle Clock Suspension, March 1980
26 The Development of Batteries for Electric Clocks and Watches
27 Electrical Horology Group - The First Ten Years
28 The ATO Electric Clock
29 An Early Electric Clock System
30 The Role of Electrical Horology in the Development of the Quartz Clock
31 Master Clock - Quartz Controlled Time Transmitter
32 The "Chronopher" Master Clock System
33 The Construction and Early Development of the Talking Clock
34 A Proposal for a Time Ball at Boston, USA
35 List of Major Electric Clock Literature available from The Franklin Institute Library, USA
36 The "Synchronome" Astronomical Regulator>
37 Improvements to Astronomical Clocks
38 Stored Energy Power Supply for Synchronome Impulse Systems
39 Adjustments to the English Clock Systems Master and Slave Clocks
40 ITR/IBM Supervised Time System - Principle of Operation
41 Hints for Servicing Pulsynetic Clocks
42 Electromagnetic Clock Literature of the 19th Century
43 Telephone Manufacturing Company Ltd. High Movement Impulse Transmitter
44 Electric Clocks in the Science Museum Reserve Collection
45 The Greenwich Mean Time System
46 Time in Broadcasting
47 The Latest Developments in Quartz Crystal Oscillators
48 The Telephone Rentals Uniselector Chronogram
49 The Electric Clock Systems of the London Underground
50 An Earth Cell Experiment
51 National Time Standards
52 Almost Perpetual Motion - The Amazing Clinker Pendulum Clock
53 100 Years of the Domestic Electric Clock
54 (The Bulle Clock - Practical Manual) Available as a book from the AHS
55 The Fedchenko Isochronous Pendulum Suspension Spring
56 Catalogue of Exhibition of Electrical Clocks Working on the Hipp Toggle Principle
57 Matthaus Hipp of Reutlingen
58 Smiths - An Overview of Their Activities in Electrical Horology
59 Warren's Synchronous Clocks
60 Ffolliott Gray's Invention "The Duo Electric Clock"
61 Siemens & Halske Electric Clocks 1847-1945
62 Post Office Clock Survey
63 "Clocks Magazine" - Electrical Horology Index
64 Gillett & Johnston Master Electric Clock - Setting up and servicing
65 Rabe Bros. of Hanau - Torsion Pendulum Clocks
66 The Beginning of the Liquid Crystal Watch
67 Pul-Syn-Etic clocks, Installation, Maintenance and Repair (Revised plus supplement)
68 English Clock Systems Ltd 1-Second Master Clock
69 Gent Fig.C53 Strike Controller
70 100 Years of Paul Schroder of Stuttgart 1902-2002
71 The Quartz Revolution
72 Master Clocks Designed & Manufactured By Gent Ltd - 1898 to 1980
73 A Celebration of the Centenary of the Eureka Clock Patent
74 The Lowne Electric Clock Company - History & Servicing the Master Clocks
75 Servicing Procedures & Catalogue Details for the TMC 'SPB' Half Second Master Clock
76 Bulle: A Study into the Effectiveness of the Isochronous Spring.
77 An Approximate Expression for the Effect of the Bulle Isochronal Spring
78 Frank Holden – the Man and his Clocks
79 P A Bentley - The Man and his Clocks
80 Recollections of 40 years of the Electrical Horology Group
81 A Game of Numbers - some observation on serial numbers
82 English Clock Systems Ltd - Revisited
83 Telephone Rentals and their activities in electric clocks
84 Battery Insertion Movements DVD
85 Searching Patents
86 Stanley John Wise - The Author and His Electric Clocks
87 An earth cell investigation
88 Index of electrcal items in Clocks Magazine - Paper No 63 update
89 Tayco clocks
90 The ‘Wallace and Tiernan’ Electric Clock

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Group Meetings 2017

Saturday 10 June

2:00 pm at The Clockworks, 6 Nettefold Place, London SE27 0JW
LECTURE: ‘The Ups and Downs of the Greenwich Time Ball’ by Anna Rolls, Royal Museums Greenwich

Gents C6/C7 Master Clock Survey

Started in 2007, the Gents master clock survey can now be completed and submitted electronically. Full instructions are on the first page of the survey document.
Click here to download the survey file (pdf 1.7MB)


Gillett & Johnston master clock

Gillett & Johnston master clock