Paul Philip Barraud

For reasons that I cannot explain even to myself, I have always had a fondness for the clocks and chronometers made by Barraud and his later company Barraud and Lund.  Sadly I have had only one connection with one of their products, a Ca. 1818 marine chronometer (one that is listed in Jagger's* supplement as being issued to a Captain Mills of the ship Asia in 1851).

 

* Paul Philip Barraud and Supplement, Cedric Jagger, The Antiquarian Horological Society, 1968 and 1979: “Probably Marine.  Listed in the [ Clifford Lupton (Cornhill) Rating Book ] under ship: Asia, Capt. Mills.  January - March 1851.

 

     Recently I was invited to service a really lovely rosewood fusee timepiece, the dial  bearing the name Barraud and Lund, Cornhill, which is illustrated on the cover page of this edition of The Micrometer.   To my inexpert eye this timepiece seemed pretty genuine, and the only reason it had come in to my workshop was due to a heavy gumminess in the lubricants causing it no longer to run.  Clearly this was one for a conservation approach, and pleasingly little needed doing to it, the most significant perhaps being to replace a missing glazing bead from one of the bevelled side glasses.  To me, this replacement was an essential job if the glass (held in place only by the remains of some animal glue or shellac) was not to drop out and possibly get broken.

     I always like to note down any maker's marks or graffiti, and this one had something I have not seen before: a scratched inscription inside the barrel cover which can be seen below.  It seems to say 'M/SPG 11/1982 R Hurst(?)' from which it is perhaps reasonable to deduce that the mainspring was replaced in November 1982 by the repairer R Hurst(?).

 

 

     Returning to my marine chronometer, it is nice to believe that the ship Asia to which it was issued might have been the 2,200 GRT Cunard paddle steamer built in 1850 at Greenock.  Constructed of wood, she was one of the six America-class Royal Mail Steamships designed to ply between Liverpool and North America, and a photograph of a sister ship, the Europa, is reproduced below.

 

  

Photo: Wikimedia Commons

 

     But this belief could well be flawed for the simple reason that I have been unable to find any reference to a Captain Mills serving in 1851.  Moreover, was it likely that a ship plying out of Liverpool would ever have had its chronometer rated by Lupton of Cornhill (London)?  Was there a transcription error by Jagger (or Lupton - I have not sighted the source document) and Captain Mills actually should read Hills, Wills or even Miles?  Was Captain Mills of the private sailing ship Asia built in Aberdeen in 1818 engaged firstly on the convict trade to Australia and latterly as an immigrant ship?    Or was he a naval officer serving in HMS Asia, a second rate ship of the line built in Bombay in 1824?

     At the moment, I just don't know, so further research is essential before any substantiated view can be offered.

 

 

 

A fine bracket clock

This superb Ca. 1790 to 1800 ebonised striking and repeating bracket clock had stopped, the primary reason being the heavily oxidised and congealed oils coupled with heavy scoring to the back third arbor pivot.  But in all other respects it was in excellent condition, and was a tribute to the last repairer.

 

 

     The photo below left shows the beautifully engraved backplate so rarely visible when the clock is on a bracket or mantel, and (upper left) I have endeavoured to extract a close-up showing two filled-up potence holes which suggests that the clock would have had when originally made with verge and crown wheel escapement.  Being far more tolerant of the clock being moved from room to room, the verge escapement would still have been common for bracket clocks of the late 18th century.  The right hand image shows the back of the dial plate and the date actuating mechanism.

 

 

     But as always, it is important to take the mainspring(s) out of the barrel to check all is well; if one does not, there is always a chance of not spotting an incipient failure.  And so it was with this clock, and below I showing the problem.  Note how the hole in the outer end of the 40mm wide x 0.5mm thick mainspring had been left with sharp corners, so guaranteeing the initiation of the cracks that can be seen from each corner in the upper enlargement.  It would be lucky to survive for more than a few years in this condition.  My remedy (which unfortunately I failed to photograph) is shown in the 'before' and 'after' sketch to the lower left: in the right hand sketch note how the cracked material has been completely removed and the hole corners well-radiused.

 

 

     In steel, two things are needed for crack initiation: a high (generally cyclic) load and a structural discontinuity.  The steel's use as a mainspring guarantees the former, and the sharp corner detail - almost certainly an error by a previous repairer - guaranteed the latter.  In this mainspring I was lucky firstly to have spotted it before the cracks had extended to more than about 5x the spring thickness (5 x 0.5mm), and secondly that there was sufficient material between the eye and the end of the spring to allow the cracks to be removed.  Of course, failure to remove the cracks completely would achieve very little as the intense stress concentration would remain at the unremoved crack tip.  Not being easy to see, a rule of thumb is that one must assume that the crack extends at a microscopic level for at least, say, one material thickness beyond the end of the visible crack tip.

 

 

Timing the bracket clock

As is customary, I took a going train count while the clock was in pieces which revealed the following: centre: 84T; third: 7T, 78T; 'scape: 7T, 32T.  This train count enabled me to determine the beats per hour so that a good shot at the correct rate could be made on preliminary timing.

     For timing I use a Mumford Microset timer ( http://www.bmumford.com/microset.html ), and if at all possible I make use of the optical sensor which avoids all the problems of extraneous clunks and clicks associated with using an acoustic sensor on a striking clock of this age.  The first thing I do is to set the count period to the number of 'scape wheel teeth, so in this case the count period is 32 beats.  Setting it to twice the number of teeth (which in this case would be 64) has advantages if there is a suspicion that the 'scape wheel teeth may be uneven (think about it).  The photo shows the preliminary measurements being taken, with the inset showing the bob swinging.  The one thing I do recommend is that you set the optical sensor as close to the mid-point of the pendulum swing as possible(see photo), especially if not using a count period of twice the number of 'scape wheel teeth.

    And what is the correct number of beats per hour?   Students of horology will have absolutely no difficulty in getting the correct answer from the train count I mentioned above, but if you want to check your arithmetic, see the bottom of this page (and no, the rate shown on the Mumford is not the correct figure).  This is not because the Mumford is not accurate but because a point sample can never be accurate for a spring-driven fusee clock designed to run for 7 days.  In addition to atmospheric conditions, factors affecting the clock's timekeeping include demands made on the going train from operating the strike and date work, and the variations of driving torque that will inevitably occur due to less than perfect mainspring/fusee matching.  True accuracy, which I define as the clock showing the same time at the end of the 7-day running period as it showed the start, can only be determined by running the clock for 7 days.

 

 

 

 

One that got away...

Checking a mainspring's ends out of its barrel will enable one to discover most mainspring defects, but below is one that I didn't spot.  This 19mm high strike mainspring from a two-train carriage clock seemed to be in good condition, but when the clock was reassembled something was not at all right.  When removed for a second time, the spring came out in two pieces, the fracture being about 50mm from the inner end.  In this case the granular appearance of the fracture surface suggested a brittle failure caused by a metallurgical defect on manufacture.

 

 

 

... and one that didn't

Checking the ends of the mainsprings of a Handley & Moore movement fitted to an early 19th Century striking bracket clock, the going mainspring (measuring 38 mm x 0.50 mm fitted in a barrel of 55 mm inside diameter) was not of recent manufacture to judge from the surface finish and its relatively low temper.  But unfortunately the inner eye was starting to tear - see the photographs of the inner and outer surfaces below.

     Normally it is the outer eye that tears, which is an easy matter to crop, temper and re-form the eye, but to do the same to the inner end is hugely difficult without reverse-winding the tremendously powerful and finger-lacerating mainspring.  Inevitably involving plastic deformation of the steel, to do this successfully without heat treatment is fraught with difficulties in 200 year old steel.

 

 

Now I am loathe to replace mainsprings in antique clocks, and I did not want to try to re-make the inner eye for the reasons just mentioned.  If I was to avoid replacement, the only option seemed to be to take a chance that the crack was benign (not propagating), but how was I to judge whether this was so?  For example, had the crack initiated months, years, decades or even a century ago?  And even if I knew this, was the 3 to 4 mm length it had now reached the end of its run or was it still propagating?  And if it were still propagating, sooner or later the mainspring would fail.

     I simply did not know how to attempt to answer these questions.  Even if money were no object and one could quantify the normal and shock loads (the latter perhaps caused by the impact of the fusee with the stop iron if vigorously wound), destructive testing of the steel in a fracture mechanics laboratory might reveal a solution but would rather defeat the purpose of preserving the mainspring in the clock.  And as the owner kept the clock running in pride of place on the mantel, I felt the only option was to fit a replacement, the old spring being well-packed up along with my notes and photos before securing clear of the pendulum below the seatboard.

 

 

 

Steel pallets

A little further up this page I wrote briefly of cracking in steel.  For the second time in as many months I have seen recoil pallets in a rather cracked state, so I photographed (below) one set, which were taken from an early 19th Century longcase clock.  My initial thoughts were that they might have been weld-repaired, but I do not think so.  I also wondered if a new piece had been fitted, but in the lower (enlarged) pallet I could find no sign of solder or brazing filler. (The other (upper pallet in the photo) had had a piece brazed on, hence the visible line.)  So far I am left with but one conclusion: it must be simply fracture (verging on shattering) in 'dirty' steel caused by high-rate quenching in cold water or even brine.  Any thoughts?

     As to what I did?  Well, the loads are incredibly low and 'prodding' did not indicate any bit being in imminent danger of dropping off, so as the drops were good and the wear light by longcase standards, I just gave them a clean and a light polish on the basis that they should see out at least another 20 to 50 years service.

 

 

 

 

Key piece

What an engineer would call a slip washer, the key piece on fusees on spring driven clocks and barrels of weight-driven clocks is a most ingenious low-profile solution for retaining the ratcheted great wheel.  But its retention by a taper pin (as in earlier clocks) can cause real problems during disassembly.  Frequently hammered in tightly with little excess length showing by which it can be gripped, its removal can be difficult.  Resorting to pincers can easily result in what little is sticking up being snipped off, which then requires the slip washer (sorry - key piece) to be bent out of shape to permit removal of the great wheel (after which the offending pin can be punched through from the other side of the great wheel).

     The longcase movement mentioned above (photographed below before the backplate was refitted) suffered from a very tight pin, and the stub end of the distorted taper pin made it truly difficult to remove (insert, upper centre).   So against all expert advice never to improve things, I decided to do just that by replacing it with a screw, opening out the hole in the key piece to a diameter a few thou (0.1mm) greater than the outside diameter of the screw's cheese head.  At least the key piece will continue in service without suffering destructive distortion at future services.

 

 

 

Repair to a winding crank knob

When returning a bracket clock to a customer, I was asked if I “could do something about the winding crank” for his longcase.  This was a clock I had not been engaged to service; had I done so, the crank repair would have been part of my service.   The crank was a reasonably good fit on the winding squares (about a size 13 or 14 (5.5 mm or so)) but the knob was in two halves held together with binding twine and bell wire (photograph).  On separating the two halves of the knob, I was pleased to see that ’Seccotine man’ was nowhere in sight, no attempt having been made to glue the halves together.  This was good, as removing old glue in order to reveal bondable mating surfaces is never easy.

 

  

 

     I cleaned off the loose rust from the knob arbor and gave it a wipe of petroleum jelly.  Two subsidiary cracks in the ebonized hardwood knob were dosed with cyanoacrylate superglue, applying some minutes later a thin film of Araldite epoxy adhesive to the bare surfaces of the two halves of the knob and clamping firmly together.  Once cured the epoxy was trimmed off and the knob finished with one coat of black French polish followed a day or so later with black wax polish.

     Concealment of the broken joint is not perfect, but then the rest of both the knob and the crank was also a little ‘action damaged’.  To have made the knob more perfect by filling and sanding would have required quite a bit more work and would probably have made it looking disproportionately new.   I like to think I stopped my renovations at the right time.

 

 

 

St. Peter's Church, Sandwich

The redundant church of Saint Peter's now in the care of the Churches Conservation Trust has a tower clock which the Trust has expertly made accessible for visitors.  Made in 1887, the turret clock is by Gillett & Co of Croydon, and the visitor has full access to the bells by an ingeniously-constructed stairway that goes right through the centre of the bell frame.  One can also get onto the roof of the tower for all-round views of the surrounding townscape and further distance.

     A plaque affixed to the bed indicates the automatic rewinding mechanism was designed by Alderman A H Jutson and manufactured by the pharmaceutical company Pfizer Ltd. for installation in the Church in 1965.  Some further information on the Church and visiting details can be found at https://www.visitchurches.org.uk/visit/church-listing/st-peters-church-sandwich.html

 

   

 

 

 

The 'real' Talyllyn railway

 

In the January 2017 edition of The Micrometer I included a photo of me on our 3½ inch gauge Tal-y-llyn track.  Completed in 1973 with the help of my father, the track can be seen running along the bottom of the lawn in the photo below (1980).  Tal-y-llyn Lake (Llyn Mwyngil) is behind the boscage (a word well-known to TR volunteers), and the Tyn-y-Cornel hotel is on the opposite shore.

 

 

     The track bed consists of commercial 440 x 215 x 215mm concrete blocks bedded onto a shallow foundation of slate shale, the upper decking being formed from pre-cast slabs of concrete 900 x 50mm thick.  These slabs were cast on-site three at a time in timber formers.  Using extruded flat-bottomed aluminium rail in 3 metre lengths, the sleepers cut were from 25 x 25mm section paper-reinforced Bakelite jig-drilled to take screws to secure the rail to the sleepers by means of the underside of the head of self-tapping screws.  The pre-assembled lengths of track were bedded into mortar, and the rail ends joined by fishplates cut and shaped from steel strip.  Although only 50 metres long, the track saw service for around ten years during which time it suffered no track movement or degradation.  I and my brother enjoyed regular 'steam-ups' of our two 'LBSC' designs - Tich and Betty (seen below).

     No trace of the track now remains, but perhaps a few Talyllyn Railway visitors might just remember it when they had an awayday from the other Talyllyn Railway?

 

 

 

 

 

Next time

 

A disc facing attachment for the Myford Super 7 lathe, and the first part of a photographic essay in the construction of a 3½ inch gauge live steam locomotive boiler.

 

 

 

 

Guy Gibbons

 

 

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Timing a bracket clock:  (84/7) x (78/7) x 32 x 2 = 8557.71 beats per hour.

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The Micrometer

A bi-monthly review of the engineering of time

Issue 7   September - October 2017

Copyright (c) 2017  G E Gibbons

The Micrometer

A bi-monthly review of the engineering of time

Issue 7   September - October 2017

The Micrometer

A bi-monthly review of the engineering of time

Issue 7   September - October 2017

Copyright (c) 2017  G E Gibbons