Saturday, 29 July 2017

Colonel Péchot – it’s personal

Prosper Péchot was first and foremost an artillery office. Before he developed his system of 60cm railways, he invented an automated range-finder for gunnery. It was in fact an analogue computer!
Prosper Péchot 1849-1928 Photo courtesy of Raymond Péchot
The description given to the French Patent Office described it as ‘a device’ which can be added to existing range-finders ‘to find the range automatically’. The device could be fitted to cylindrical rangefinders or ones consisting of steel ribbons. The machine à diviser (range-finder) which Péchot intended to improve was one invented by a M. Guyenot which depended on a steel ribbon. In the field, this proved inflexible as the range could only be found to certain arbitrary measurements. The drawing accompanying Péchot’s patent application shows an impressive array of cogs and levers which attached to the existing range-finder. One thinks of the Babbage Difference Engine. 
Almost programmable. One detail of sketch which accompanied Péchot's patent application

Another detail Péchot's analogue computer. The handle shown above turns the gear. Both pictures courtesy of Raymond Péchot
Wouldn’t it be wonderful if one was to be constructed! The patent refers to discussions held in 1879-80 when Péchot was at Bourges. The reference is
no: 777The patent was lodged on March 7th 1880 at the Prefecture of Cher.
The full story is in my book ‘Colonel Péchot: Tracks to the Trenches’ chapter Two.

There are parallels between the story of Prosper Péchot and some of my own family.  My great-great grandfather, David Davidson, 1811-1890 invented a related device, a collimating gun sight.
He had always been interested in ordnance. As a boy, he invented a crossbow of ‘peculiar and novel construction’ from which he could shoot pellets with precision. His targets were sparrows, needed as food for his pet sparrow-hawk. He used the top of the family’s weather-cock for target practice; the workman sent to repair it looked down on the young shot. He favoured him with a look and a shake of the head but did not tell. He also ‘peppered’ the monkeys of the local travelling circus (Wombwell’s Menagerie). Being used to projectiles, the monkeys were neither hurt nor surprised  but disappointed to find that Davidson’s missiles were not edible.
When he was fourteen, his target was Sandy the gardener. Sandy was seventy yards away and foolishly said to young Davidson ‘I’ll wager you’ll no hit me’ This was a tempting challenge and he ‘hit him in a safe place’ – I assume his bottom. Sandy admitted it was quite sore. Such merry japes continued until he was packed off to India in 1827 to become a servant of the Honourable East India Company.
The Indians he met were a good influence on him. For the rest of his life, he held them in respect. He developed his original ideas, first being a sort of blow-pipe to which he attached his design of telescopic sight and indulged his love of hunting. In those days, the only good tiger or cobra was a dead one – sad but true. 
In 1839, he wrote a paper entitled ‘Rifled Cannon’ which was brought to the attention of the Duke of Wellington. The crusty old war-horse wrote back a lengthy criticism to the effect that rifled cannon were an impossibility. His paper was better received by the Royal Society when it was read in Edinburgh by Professor Piazzi Smyth.
Years later, projectiles were made with copper studs which could engage in the rifling. Sir David claimed that ‘the principle was the same’ and that he had been justified! Pic p215
David Davidson's innovation. At the top is a cross-section of the gun barrel showing grooves in the gun barrel. Below are sketches of the shell shown in crosssection and lengthways. In the system that was subsequently adopted, copper studs rather than continuous bars were used. Picture courtesy of the Davidson family
An early version of a telescopic sight was shown at The Great Exhibition of 1851.
Soon, he and his friend Professor Piazzi Smyth were working on improvements. When the Crimean War was in progress and the British gunners hit a problem with Sebastopol. They could spend a whole day pounding at the defences with their guns. While they rested at night, the Russians went and repaired the damage so that ‘in the morning the assaulting party … instead of a practical breach … were faced by fresh (enemy artillery)’.
Davidson’s idea was to register the British guns so that they could keep up their fire with equal precision at night. His invention was tried out at Woolwich but the siege of Sebastopol was over before they could be used. He had the comfort of being told by Sir J.H. Lefroy of the United Service Institution that ‘if such as siege as Sebastopol were to occur again, (he) had no doubt this instrument would be deployed’
In practice, the recoil of heavy artillery would upset careful calculations but this was not an end to his Collimating Telescope. In 1858, he was invited to fit an improved version of his new Collimator to a Whitworth rifle. He heard nothing more. Later a friend researched the matter and found that 100 Whitworth rifles fitted with his sight ran the blockade and were used by the Confederate side, from Shiloh to Beatonside.
So armed, the Confederate snipers were deadly. They could fire to a range of 2200 yards (1.98 kilometres). The new sight was also used by the other side. A small body of Federal snipers equipped with the new gun-sight kept a Confederate battery silent for twenty days. When the position was taken, they found 50 gunners had been killed, chiefly by head shots, from a distance of 1100 yards (0.99km). The heads of the targets could not be seen with the naked eye.
The new sight was not adopted in Britain. Davidson described the blunders of the testing committee and ended with: ‘Inventors outside the dominant clique have a poor chance of fairplay’.
Davidson’s invention, was based on a device used by astronomers. It needed a small lantern and came in a carrying case. When setting up, the carry-case could be weighted (Davidson recommended the use of lead shot) and was then used as a platform for the device. Where two sets of cross-hairs intersected, as shown in his diagram, the aim was registered.

It could be adapted for field mortars, he commented.
Davidson returned  from India in 1850. He and his wife lived in Edinburgh but later on, they had a summer residence in Aboyne. They raised a family of ten children, five boys, five girls.
In 1880, he published his ‘Memories of a long life’. The book has recently been relaunched in the USA.

Tuesday, 18 July 2017

Four Bagnall Excelsior models nearly ready

Thank you, everyone, for your enquiries about Malcolm’s batch of 16mm gauge ‘Excelsior’ locomotives. She is a locomotive that Malcolm always loves building. They are proceeding to the ‘paint-shop’ to be primed and we are checking the order book for potential customers.
Four 16mm models of the Bagnall 'Excelsior' wingtank made byWrightscale. They are in the 0-4-0 configuration with spark arresting chimneys - more about the history below.  Photo MD Wright 
This is a locomotive which has always interested and mystified people. It is particularly tiny – only 3 tons 15cwt (3.8 metric tonnes) – in working order. The original maker’s records are sparse. 'Excelsior' was Bagnall Number 970, completed February 1888, 2’ gauge, wheelbase 3’, cylinder size 5” by 7.5” (metric equivalents 60cm, 90cm, 12.5cm, 18.75cm). It was supplied to Christopher Naylor for a tramway on his Kerry Estate, Mid Wales. In 1895, it was sold to J.Nuttall, Manchester, the contractor building the  Lynton and Barnstaple Railway in Devon. When that construction job was completed, it was bought by F.J. Barnes, Isle of Portland, for stone quarrying operations.
For a long time, it was assumed that Excelsior left Bagnall’s in 0-4-2 configuration although this is not implied by the information in the Order Book which just mentions that the wheel-base was 3' - simplest interpretation 'two axles three feet apart'. In fact, it is quite fascinating how many books perpetuated the myth. It shows, firstly, how many authors were interested in the tiny locomotive and secondly how deeply a myth can become entrenched.
The ‘myth’ was finally busted by Phil Copleston and Roy Link. Phil had been asked by Mrs Chadwick, the local landowner, to look through the researches of her late husband. Having traced much of the permanent way of the Kerry Tramway, Phil searched Mr Chadwick’s papers. There was a photo, admittedly a blurred copy of a copy, showing an 0-4-0 with the distinctive ‘Excelsior’ name-plate and general profile – though rather shorter and sporting a balloon-style chimney. The locomotive was surrounded, as Excelsior always was, by affectionate workers in late 19th century costume. Acting as devil’s advocate, Roy Link scanned the photo and set about checking that it was not a hoax.
THis 'three quarter' left hand side' viewof the 16mm Wrightscale model shows the Bagnall as it appeared in the Chadwick photo which has been dated to around 1890. The locomotive was clearly a compact 0-4-0, with balloon stack chimney.  Photo MD Wright
We can believe our two professionals. Meticulous scanning of the copy showed no sign of tampering.  The photo had provenance. It had been copied from an original in the archive of Severn Press, though it has not been possible to trace where this original went. This photo was genuine.
It gave us some interesting extra information. As before mentioned, it showed the locomotive in 0-4-0 configuration. It has the distinctive profile which is confirmed by later photos, and the spark arrester which appears in one photo taken on the Lynton and Barnstaple. It is running on very light track, laid on rough sleepers, little more than logs. The tramway was short, little more than 3 miles (5 km). The locomotive was tiny, well adapted to such light track. The short duration (small tanks and bunker) were hardly a disadvantage when runs were so short. All in all, it was well adapted to C. Naylor's requirements.
Once it left the Kerry Tramway, Excelsior was photographed several times. One phot, dated 1896-7 (perhaps in early summer) shows her at Barnstaple. She has now been fitted with a back extension – evidence that she now has the trailing wheels – but she still has her American style logging railway chimney. The most celebrated view which must have been taken in winter shows her with a stove-pipe chimney. The back extension is shown quite clearly. In all likelihood, these were fitted when she was sold, probably by Bagnall's.
Excelsior finished her life at the Isle of Portland Quarries. Her job was not glamorous, heading a train of skips taking quarry waste to the edge of the island for disposal. Even then, she featured in a postcard entitled ‘The Quarry Express’. A last photo shows her, in the words of Roy Link, looking weary. (Narrow Gauge and Industrial Railway Modelling Review Issue 53 page 197) The smart platework at the rear has been replaced by corrugated iron and even the name plate has lost its lustre. At some time in the 30s, she was taken back to the contractor’s works at Easton, central Isle of Portland, where she stayed until cut up for scrap. We believe that this was well before 1953 when the Isle of Portland Railways were officially wound up. However, even here there is not complete certainty.
16mm Wrightscale Bagnall 'Excelsior' Most photos show the locomive from the right,, though in 0-4-2 configuration and sporting a back extension. This would have accommodated another water tank to extend her duration.
This little locomotive inspired affection in the people who worked with her, always eager to appear in photos. Eight photos survive, a remarkable number as Roy Link comments ( NGI Review page 193). Phil Copleston, Roy Link, B.L Jackson, L.T. Catchpole, J.I.C. Boyd and Lewis Cozens, to name but a few, found her interesting enough to break off their narrative to describe her and her history.
So what, the anthropologist might ask, is her appeal? Clearly, her characteristics and unique profile are important. She also stands out because of a tinge of melancholy. She only worked on the Kerry Tramway for a few years before it was dismantled.  Her next owners went out of business building the Lynton and Barnstaple Railway. She then went to the Isle of Portland. In thirty years, the Isle had gone from medieval, run by Court Leet, to booming provider to the Building Trade. In the 1930s she shared in the slump and the death of the industry. As with her inception, mystery hangs about her end.  
Excelsior in 0-4-2 configuration, showing nameplate. 16mm Wrightscale model (not for sale) photo MD Wright
Her name is important, the Excelsior plates appearing so prominently in right and left views throughout her life. The brief mention in the Bagnall order book does not indicate if the plates were factory-fitted. Clearly, throughout her history, no-one thought to change them or melt them down for scrap. Even when there is a crowd around her, the nameplate stands clear and visible. Her name was, the anthropologist might think, part of her mystique.
Excelsior means ‘Higher’ in Latin; the name has clear links with ‘Excellent’,but for centuries, the term was only of interest to Latin scholars. At the time of the Revolution, New York State took Excelsior as the motto for its official state seal. In the 1860s, the term went mainstream; New York became popularly known as the Excelsior State. It was in due course adopted as a trade name in the USA (for a patent mattress stuffing, since you asked).
Why did the first owner of the locomotive, Christopher Naylor, like the name? Perhaps there was some connection between the family and New York State. Even the idea of a logging railway is American. To a less cynical age, it suggested self improvement and aspiration.Answers on a postcard, please!
The view that never was, TWO Excelsiors! 16mm models by Wrightscale