26 July 2010 - How Clocks Were Made in the 18th and 19 Century

The availability of electric power, whether it be at home or in the workshop, has transformed our perception of manufacturing to the extent that it is very difficult for us to conceive how instruments were made in the 18th and 19th centuries.  Yet in lamp-lit workshops and with the use only of hand and hand-driven  tools, this is exactly how the clocks we admire, repair and restore today were made.

Through his painstaking detective and forensic research, BHI silver medalist John Robey held an audience of some twenty-four members spellbound at our July meeting with his well-illustrated talk showing just how many components of a typical longcase clock movement were made without either the use of motorised lathes or a ready supply of rolled or drawn brass materials.  Central to the methods were the use of calamine brass castings and wrought iron forgings for the majority of parts, the brass possibly from the former local brass works at Saltford.  By the first half of the 18th century 'kits of parts' were increasingly used by makers; these included cast plates, knopped pillars, wheels ready crossed out, collets 'by the stick', and even slipwashers, while wrought iron forgings were supplied for springs, levers and arbors, the latter slit to leave the maker with the job of rounding the tips of the pinion leaves.  Even iron strike-work posts were supplied ready-tapered; a convenience to suit the tapered bores necessary to provide a secure fit on the tapered arbors in the hand driven lathe while turning the outer profile (three-jaw chucks were not available).

The talk was masterly, and this brief write-up cannot even scratch the surface of the depth of material John presented.  If you haven't heard the talk, then a conversation with your branch programme secretary is definitely appropriate.......

Guy Gibbons MBHI

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26 April 2010 - Watch Servicing; the Smiths Calibre 1215



There is an innate human fascination in watching others work, whether it be digging a hole or re-assembling a watch and, one can be sure that observers with some knowledge of the processes will not only be admiring but also inwardly criticising in equal measure.  At our April meeting those seeking to criticise would have been sorely disappointed as our own Owen Gilchrist (at right in photo) faultlessly reassembled and lubricated a Smiths Calibre 1215 watch movement before a well-attended meeting.
For this year's demonstration, Owen worked under a live video camera displaying all he was doing on a large screen.  The speed and dexterity with which Owen worked was truly amazing as he tweezered effortlessly into position each screw and engage the screwdriver blade without slip or mark.  After the demonstration, Owen was quite literally mobbed late into the evening as he provided close-up demonstrations in response to individual questions.
Introducing his presentation, Owen talked a little about the history of Smiths watch-making at Bishop's Cleeve, Cheltenham, from just after World War II until before manufacture ceased around 1970.  The uncomplicated Smiths Calibre 1215 is a superb piece of English design and manufacture, being reliable, robust and easy to service.  Indeed, it was a Smiths 1215 that Sir Edmund Hilary chose to wear to the summit of Everest in 1953, which is surely a more hostile environment than the surface of the Moon?
Bristol Branch is greatly honoured to have Owen as a member, and the time and immense enthusiasm he devotes to the BHI.  Owen, thank you.

Guy Gibbons MBHI


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29 March 2010 - Clock Conservation and Microwelding


Geoffrey Walker FBHI and his wife travelled from Manchester to talk about clock conservation and microwelding.  Geoff has had a lifelong interest in horology; he completed the BHI Horology course at Manchester College, where he was awarded National and Branch prizes for the high standard of his work, and then studied at West Dean College.  Geoff outlined his very sympathetic approach to clock conservation, which includes 'not doing what doesn't have to be done', and 'trying to avoid as many restorative actions as possible'.

He discussed bushing, pivot, wheel and hands repair with particular emphasis on removing as little as possible of the original clock materials.  The theme of the talk then progressed naturally to microwelding, where replacing small amounts of metal onto an original worn component is relatively easy.  The welding process involves creating a weld pool and melting filler wire into it, adding to the metal already present.

Geoff showed images of examples of badly worn pinion leaves, pallets and pivots which had been filled and repaired.  He also showed how he profiles and polishes the repair, leaving the original component fully usable again.  Such conservation and repair is of enormous advantage where making a new replacement component is undesirable.

The downside for many horologists is that the high initial price of a microwelding machine may make it an unviable purchase, however Geoffrey may be able to assist with repairs.  His web site address is:
www.geoffreywalkerclocks.co.uk

A most interesting and very well-attended talk.

Malcolm Pipes FBHI

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22 February 2010 - Horology and the Industrial Revolution

Consider a 16th/17th century Protestant England free from the Roman church's proscription preventing scientific debate into the understanding of planetry motion and time-keeping.  Move forward to an 18th century nation comfortably-financed (directly and indirectly) by the Royal Navy.  Scratch the surface of the great names of British industrialisation - Newcomen, Watt, Boulton, Arkwright, Huntsman, and many others - and one will find horology as a common apprenticeship or trade.  There could only be one possible outcome; the Industrial Revolution, in which science and engineering of horology played a crucial role.

This was the subject of our well-researched talk by Robert Loomes.  There was stability in England not enjoyed by her revolution-torn neighbours.  Gentlemen had disposable income to support scientific exploration and manufacture.  Newton had laid the groundwork for the classical mechanics of gravitation (and pendulum theory) in his Principia.  James Watt studied instrument making in London and was a spare-time clockmaker.  Richard Arkwright describes himself as a clockmaker in his Spinning Jenny patent.  Benjamin Huntsman, frustrated by a lack of clean steel needed for his clock, lock and toolmaking business, successfully produced in commercial quantities the one material that most characterises the Industrial Revolution: steel.  What was clear is that England alone had the building blocks in place necessary for an industrial revolution to take place.

The role of the guilds was also mentioned: were they help or hindrance?  Did so many horologists provide the foundation for the Industrial Revolution because of their scientific ingenuity and engineering skills, or was it because they chose to abandon the horological trade in frustration with guild-imposed restrictive practices?

Tracing its roots from Elizabethan times, the evidence Robert brought to support his thesis was compelling, and positively peppered with snippets of information that built up to develop the whole picture.  A superb talk superbly delivered.

Guy Gibbons MBHI

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25 January 2010 - The Pump Room Tompion

Stephen Clewes, City of Bath's manager of the Roman Baths and Pump Room, gave the 2010 programme an excellent start with his talk on the Pump Room Tompion.  One of 5 extant equation clocks by Tompion, this month-going example was presented by him to the newly rebuilt Pump Room in 1709.  Housed in a 9ft tall oak case in the form of a Doric column, the timepiece's equation dial in the arch is fixed, a hand registering the variation between solar time and mean time.  The accompanying sundial (an essential accessory for an equation clock), also by Tompion and 'improperly removed' in 1838, was rediscovered in a Tetbury garden before being restored to its original location in 1971.  Tompion's first visit to Bath, probably to take 'the cure', was in 1705 when Richard (Beau) Nash was the master of ceremonies.  For 18th century wealthy and aristocratic visitors, Bath was the height of fashion, as depicted in popular cartoons of the day by Thomas Rowlandson and John Nixon.  These show the Pump Room interior and the clock case painted white with gilding, though no traces of paint can be found on the case today.  The present Pump Room was opened in 1795, the clock positioned as it is today beneath a statue of Beau Nash.  The Branch is fortunate to have such an important clock on its doorstep and several members are looking forward to attending a special 'Spring forward' breakfast hosted by Stephen in the Pump Room.


Trevor Waddington FBHI

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30 November 2009 - Captain Cook, Venus and a Great Discovery



The Branch was pleased to welcome Philip and Jeanie Priestley, who have been highly popular guests on many occasions over the years.
Philip related that in August 1768 HMS Endeavour departed Plymouth for Tahiti on an expedition to measure the transit of Venus as it crossed the sun's surface.  Such transits only occur once every 113 years, with a twin crossing appearing 8 years later.  It had been suggested by Gregory and later Halley (of comet fame) that measurements of the transit and subsequent calculation could provide an estimate of the distance from the earth to the sun, which was an unknown value at that time.
The 39 year old James Cook was appointed to the command, accompanied by 94 officers, men and scientists, including the astronomer Charles Green, 2 greyhounds and a milking goat.  Cook travelled with a personal watch and Green with a watch supplied by George Graham together with 5 astronomical regulator clocks by John Shelton of London.
On 3rd June 1769, after an 8 month voyage, the weather in Tahiti was ideal for the observation but measurements were taken with some difficulty and Cook and Green were despondent about their results, although compared to modern values the result was actually reasonably good.
Sealed Admiralty orders instructed Cook to sail further and in doing so New Zealand was charted and Eastern Australia discovered.  Unfortunately, Endeavour struck the Great Barrier Reef but disaster was narrowly averted.
In 1771 Cook returned home and was treated as a hero where he was promoted to Commander, but after 2 expeditions, charting Australia and America, he was murdered by natives on the island of Hawaii in 1779.
Please note that the last opportunity to observe the transit of Venus this century will be in June 2012!

Malcolm Pipes FBHI