All posts by Graham Snowdon

Chess — Dr Phil Judkins — 20th Sept 2021

In a ref­er­ence to the often com­plic­ated tac­tics involved, cycle racing has been described as ‘chess on wheels’.   So it was per­haps appro­pri­ate that Dr Phil Judkins’ present­a­tion on  tech­no­lo­gical devel­op­ments in air war­fare during WWII should include an illus­tra­tion of a rather Heath Robinson adapt­a­tion of an upturned bicycle used to rotate a radar aerial through the required 360 degrees.

We wel­comed back Dr Judkins, who had spoken to us only seven weeks earlier and who kindly agreed to stand in at short notice when our sched­uled speaker became ill. Phil’s latest talk, Chess — Europe’s ‘Wizard War’ in the Air, to give it its full title, was a follow-up to his equally fas­cin­at­ing present­a­tion on the Atlantic ship­ping con­voys.

Phil is an inter­na­tion­ally acknow­ledged  expert on the his­tory of radar, radio inter­cep­tion and elec­tronic war­fare. Retiring from a suc­cess­ful busi­ness career, he gained a PhD in the his­tory of radar from Cranfield University, taught the MA in the History of Military Intelligence at the University of Buckingham and cur­rently researches inter­war elec­tron­ics as a Visiting Fellow at the University of Leeds. He chairs the Defence Electronics History Society.

An RAF nav­ig­ator oper­ates an H2S radar dis­play. © Crown Copyright

Phil gave us a hint of what was to come when he told us: “I’d like to recount the story about the air war which you don’t usu­ally hear — the moves in the deadly chess game between German and British sci­ent­ists, and between British and German air com­mand­ers, fought out for six years in the night skies over Europe, where all the chess moves decided who would live and who would die.”

It was chilling stuff. As Phil added, neither side had all the good ideas and neither side made all the mis­takes. But Britain, he poin­ted out, had a strange defin­i­tion of the word ‘secret.’ Tight secrecy sur­roun­ded radar devel­op­ment, and man­u­fac­tur­ers were rig­or­ously checked for for­eign con­nec­tions — or so we were told.

Prior to 1939 the annu­ally pub­lished RAF List con­tained the address and all staff details of our secret radar research sta­tion at Bawdsey, in Suffolk, and this was pub­licly avail­able from HM Stationery Office. For good meas­ure, a free copy was delivered each year to the German Embassy in London.

We built huge radar aer­i­als, 360 feet high, which fea­tured on hol­i­day post­cards. In Arthur Ransome’s “We didn’t mean to go to sea”, the chil­dren sailed back from Holland by look­ing for the tall radio towers at Bawdsey! And there was no restric­tion on where our man­u­fac­tur­ers bought their parts, so we bought from Italy, Austria and — yes — Germany.

Britain saw radar as essen­tially defens­ive. We guessed early in the war that the Germans might try to jam our radar, and our future head of Fighter Command, Air Marshal ‘Stuffy’ Dowding, had writ­ten orders as early as 1934, when he was in charge of research and devel­op­ment, that our sci­ent­ists must find a way of stop­ping enemy jam­ming.

In August 1939 the Germans loaded a Graf Zeppelin air­ship with sens­it­ive radio receiv­ers and flew it up and down the British North Sea coast, paus­ing near all the big towers of our radar sta­tions. They heard noth­ing iden­ti­fi­able as radar because they were search­ing for a system like their own VHF, send­ing out power­ful radio pulses every second. But all they found was a con­stant, low crackly hum.

The Germans looked at their map of the British national grid, and guessed that the hum came from badly-designed insu­lat­ors on the grid pylons. But by autumn 1940, as the nights drew in, the Blitz began and here the Germans were better pre­pared with not one but three accur­ate radio bomb­ing beams to aid their nav­ig­a­tion. This was a sig­ni­fic­antly better cap­ab­il­ity than the RAF would pos­sess for another three years.

In a game of chess, the final out­come depends on a sequence of moves that limit your opponent’s options and may result in tan­gible gain. In the battle of the boffins in World War II, it was thank­fully the British who even­tu­ally emerged as Grandmasters.


Living with the Mafia — Tim Stephenson — 21st June 2021

Our own member Tim Stephenson gave us a chilling insight into life – and death — under the Mafia, based on research rather than exper­i­ence. He has a spe­cial interest in Italy, having already given us two inter­est­ing talks on the wealthy and immensely power­ful Medici dyn­asty who first came to prom­in­ence in the 15th cen­tury. There are com­par­is­ons, it seems, sug­gest­ing that cor­rup­tion in Italy is noth­ing new.

Much of Tim’s present­a­tion revolved around the so-called Maxi Trial, a crim­inal trial against the Scicilian Mafia that took place in Palermo, last­ing from 10th February 1986 to 30th January 1992, and was held in a bunker-style court­house spe­cially con­struc­ted inside the walls of the Ucciardone prison.

Prosecutors indicted 475 mafi­osi for crimes related to Mafia activ­it­ies, based primar­ily on testi­mon­ies from former Mafia bosses turned inform­ants. Life sen­tences were handed out to 19 defend­ants, and 338 people were sen­tenced to a total of 2,665 years.

It was con­sidered to be the most sig­ni­fic­ant trial ever held against the Sicilian Mafia, but it was by no means the end of the story and came at a ter­rible cost to two of the prin­cipal judges, Giovanni Falcone and Paolo Borsellino, and their fam­il­ies.

Both men were assas­sin­ated by the Corleonesi Mafiosi in 1992, 59 days apart. Falcone and his wife, along with three police escorts, were blown up by a bomb which con­sisted of 200 kilo­grams of TNT and 200 kilo­grams of Semtex which had been packed into drums laid in a con­duit – which was then blocked off at either end with con­crete – under­neath the A29 motor­way. Borsellino, who had no escort, was killed by a car bomb while vis­it­ing his mother in Palermo.

Palermo International Airport has been renamed Falcone-Borsellino Airport in their memory.

Tim explained that much of the Mafia’s fund­ing came from pro­tec­tion money extor­ted from almost any­body who was in busi­ness, no matter how small. If they failed to meet the demands, they paid the ulti­mate price. We were shown grisly pho­to­graphs of the bodies of a taxi driver, a barber and a bar­tender, all of whom had met with fatal ‘acci­dents’ at their places of work.

The Mafia also per­pet­rated some spec­tac­u­lar thefts, includ­ing in 2002 that of two paint­ings from the Van Gogh Museum in Amsterdam. Both were recovered in Italy 14 years later.

Because Sicily was once an Islamic emir­ate, it is thought the word mafia might have been of Arabic origin, although this is uncer­tain. The word mā hias, or mahyas, means cock­i­ness or brag­ging.

Exploring Iceland’s Volcanoes — Dr Dave McGarvie — 22nd Feb 2021

The men­tion of Icelandic vol­ca­noes takes most people back to the 2010 erup­tion, when fine ash caused wide­spread dis­rup­tion to air flights over north­ern and west­ern Europe from April to July.

But the  erup­tions of Eyjafjallajökull in the south of the coun­try were but a drop in the ocean – prob­ably lit­er­ally for most of the ash – when com­pared with earlier recor­ded erup­tions and poten­tially even greater ones to come.

Dr Dave McGarvie, a Scot who has worked in Yorkshire in the past but is cur­rently an hon­or­ary research fellow at Lancaster University, spe­cial­ising in vol­can­ism, kept 45 of our mem­bers and guests enthralled during a one-hour illus­trated talk on Iceland and its vol­ca­noes.

This was an addi­tion to our cur­rent pro­gramme of twice-monthly Zoom present­a­tions during lock­down, brought for­ward because Dave, after being groun­ded not by vol­canic ash but by Covid-19 in 2020, is hoping to get the green light to carry out another six weeks’ research in Iceland during the coming summer.

The 2010 Eyjafjallajökul ash cloud caused so much dis­rup­tion because it was, as Dave explained, a ‘per­fect erup­tion.’ It was unusual on four counts – it occurred during a pro­longed spell of dry weather, a higher pro­por­tion than normal of the ash was very fine, the winds at the time car­ried the ash dir­ectly towards the UK and the rest of Europe, and it was unusu­ally long-lived for its size, pro­du­cing ash for 39 days.

In addi­tion, all air­craft were groun­ded because of inflex­ible flight rules.

By com­par­ison, the Grímsvötn erup­tion to the north east of Eyjafjallajökull in 2011 — known as the for­got­ten erup­tion – res­ul­ted in a 20-kilometre high plume, com­pared with Eyjafjallajökull’s plume of around eight kilo­metres, and pro­duced as much ash in two days as Eyjafjallajökull did in 39 days.

In July 2011, a few weeks after the erup­tion ended, Dave trav­elled on the first exped­i­tion to the erup­tion site to study it and col­lect samples before snow covered the evid­ence.


Dr Dave McGarvie at Grímsvötn shortly after the 2011 erup­tion.

Our next port of call during Dave’s talk was Askja, a vol­cano in the cent­ral east of the coun­try which last erup­ted in 1961 but which, he assured us, would def­in­itely erupt again. In 2014 there was a large land­slide and a ‘tsunami’ which exceeded 50 metres in height and washed a great deal of pumice from an earlier (1875) erup­tion into the water-filled cal­dera (Spanish for boil­ing pot — GS) formed by that erup­tion and, at around 257 metres, the deep­est fresh­wa­ter lake in Iceland.

Dave then took us to the espe­cially scenic Eastern Fjords, and on to Hvalsnes, which means ‘Whale Point’ where lookouts used to watch, and which has a repu­ta­tion as one of the win­di­est places in Iceland, as he found out in 2003 when the win­dows on the sea­ward side of his parked minibus were smashed by flying sand and pebbles driven by a wind of around 140mph.

Öraefajökull, Iceland’s largest and tallest vol­cano.

Öraefajökull, in  the south east of the coun­try, is Iceland’s largest and tallest vol­cano, with a dia­meter of 25 kilo­metres at its base and a height of 2,000 metres. Öraefajökull had a huge erup­tion in 1362 and its last was in 1727–28. But in June 2017, there star­ted what Dave omin­ously described as a ‘period of unrest.’

If any­body is plan­ning a hol­i­day to Iceland, that might be a good place to avoid. Or at least wear a hard hat.


  • All images via Dr Dave McGarvie

Does wealth lead to health? — Prof Tim Stephenson — 19th Oct 2020

Once again high­light­ing the depth of know­ledge within our own mem­ber­ship, we were treated to the second half of Tim Stephenson’s explor­a­tion of the immensely power­ful and wealthy Medici family.


Prior to his retire­ment Tim, a pro­fessor of patho­logy, was Clinical Director of Laboratory Medicine at Sheffield Teaching Hospitals and an hon­or­ary pro­fessor at Sheffield Hallam University. Another excel­lent audi­ence of 40 mem­bers, plus three guests from our wait­ing list, watched our latest Zoom present­a­tion, eager to hear the con­clu­sion of the Medici talk which Tim had star­ted on 3rd August.

The answer to the ques­tion posed in the title of Tim’s present­a­tion is a resound­ing “No.” The wealth side of the equa­tion wasn’t a prob­lem for the Medicis, the bank­ing and polit­ical dyn­asty who first came to prom­in­ence under Cosimo de Medici in the Republic of Florence in the first half of the 15th cen­tury.

The family, as Tim poin­ted out, was richer than most mon­arch­ies, most nations and the papacy. But their health became decidedly ‘iffy’ through a com­bin­a­tion of over-rich diet, over-protection from the out­side world and nat­ural sun­light, and over-selective breed­ing (rich fam­il­ies only inter-married with other rich fam­il­ies, in the hope of increas­ing their wealth even fur­ther).

The sub­title of Tim’s con­clud­ing talk was ‘Part 2: The Diseases, the Suffering,’ and he explained how the Medici family has been the sub­ject of medico-historical interest as many of its most prom­in­ent fig­ures were known to have suffered from debil­it­at­ing ill­nesses through­out their lives.

The risks of wealth included assas­sin­a­tion; in 1478, Guliano Medici was assas­sin­ated by the rival Pazzi family in front of 10,000 people during an Easter church ser­vice.

Although the defi­ciency of vit­amin D that causes rick­ets is often linked to the mal­nu­tri­tion and pol­luted, cramped and sun­less living envir­on­ments of the urban poor, scions of the Medici family, Grand Dukes of Tuscany, suffered from rick­ets.

In 2003, research­ers at the uni­ver­sit­ies of Pisa and Florence began the exhuma­tion of 49 Medici family buri­als in the Basilica of San Lorenzo in Florence. Nine small coffins held the remains of Medici chil­dren who had died between birth and five years of age. X-ray and osteo­lo­gical ana­lysis of the remains found that six of them had the dis­tinct­ive signs of rick­ets – curved arm and leg bones – even in very early infancy.

So these chil­dren of great priv­ilege, raised in the lap of Renaissance luxury, not only suffered from vit­amin D defi­ciency as they were grow­ing up, but were afflic­ted by it prac­tic­ally from birth. Rickets, Tim poin­ted out, is easily pre­ven­ted by eating foods such as eggs and cheese, and by spend­ing short amounts of time exposed to sun­light, which trig­gers vit­amin D pro­duc­tion. Breast milk was sup­ple­men­ted with ‘paps’ made of soft bread and apples. Neither cer­eals not breast milk con­tain much vit­amin D, and fruit con­tains none.

The Medici chil­dren, wrapped in many heavy layers of swad­dling and cocooned in grand houses, prob­ably didn’t get the same amount of sun­light as their ‘less for­tu­nate’ peers. The research­ers con­cluded that the moth­ers them­selves might have had low-level vit­amin D defi­ciency because of low light expos­ure of high-status women, or as a result of fre­quent child­bear­ing.

The ladies of the house­hold would be heav­ily made up, often using white lead and ver­mil­ion which, at that time, was derived from cin­nabar, or mer­cury sulph­ide, and — with an SPF (sun pro­tec­tion factor) of 1,000 — blocked out vir­tu­ally all ultra violet.

The Italian Renaissance princes had a much wider choice of food than other classes, but appar­ently did not avail them­selves. Historical records reveal that after meat and wine, which con­sti­tuted the nuc­leus of the nobles’ diet, eggs and cheese appear – but infre­quently. In the aris­to­cratic diet, veget­ables occu­pied a sec­ond­ary place, with an almost total absence of fruit. Gout, gen­er­ally believed to be caused by an over-rich diet, was also pre­val­ent.

Since the aver­age age of the mem­ber­ship of Stumperlowe Probus Club is well over twice the life expect­ancy of the aris­to­cratic 15th cen­tury Florentine, one can only pre­sume that we’ve all been eating our greens.


Sheffield Assay Office — Thurs 5th March 2020

I should ima­gine that 90 per cent of the pop­u­la­tion of Sheffield have heard of the Assay Office, and are vaguely aware of its role in hall­mark­ing items of pre­cious metal, but few fully appre­ci­ate its sig­ni­fic­ance on the national and world stage.

Sheffield Assay Office has been making its mark since 1773 when local sil­ver­smiths, des­pite oppos­i­tion from the Goldsmiths’ Company of London, suc­cess­fully peti­tioned Parliament for the right to assay silver in the city, and whilst it is not the oldest of the four sim­ilar estab­lish­ments still in exist­ence – the others are in London, Edinburgh and Birmingham – it is today the biggest and most influ­en­tial.

Interestingly, des­pite that early oppos­i­tion from the Goldsmiths’ Company, there are many London-based busi­nesses who choose to send their pre­cious goods to Sheffield to be assayed, and some of those cli­ents have global repu­ta­tions to uphold.

© Sheffield Assay Office

A party of 28 mem­bers and guests from Stumperlowe Probus Club enjoyed a two and a half hour visit to the Assay Office, where we were priv­ileged to be given an intro­duct­ory talk, fol­lowed by a tour of the ultra-modern premises, by Emma Paragreen, the cur­ator, lib­rar­ian and arch­iv­ist.

Emma is a lead­ing figure in the world of pre­cious metals and jew­ellery. Apart from her Assay Office work, she is a com­mit­tee member of the Silver Society and editor of their news­let­ter, and a member of the Society of Jewellery Historians and, in the last three years, has com­pleted her Professional Jewellers’ Diploma through the National Association of Jewellers. She also recently became a Freeman of the Goldsmiths’ Company.

Michael Portillo fans will have heard of Bradshaw’s, the famous ref­er­ence book of rail­way timetables. The sim­il­arly named equi­val­ent for pre­cious metals (the dif­fer­ence being that this one is still going strong), is the snap­pily titled Bradbury’s Book of Hallmarks: A Guide to Marks of Origin on English, Scottish and Irish Silver, Gold, Platinum, Palladium and on Foreign Imported Silver and Gold Plate 1544 to 2020. Daniel Bradbury was the first Sheffield Assay Master; the book is pub­lished by the Sheffield Assay Office, and Emma is the editor.

Emma Paragreen — © Sheffield Assay Office

In short, we couldn’t have wished for a more know­ledge­able person to bring us up to speed on the work of the Assay Office, whose senior staff were and still are known as the Guardians of the Standard of Wrought Plate in the Town of Sheffield. Even in 1773, Sheffield had an estab­lished tra­di­tion of fine sil­ver­ware pro­duc­tion, but the number of guard­i­ans who were also sil­ver­smiths was restric­ted in number to ten to ensure that the Assay Office offered an inde­pend­ent and impar­tial ser­vice, for the bene­fit of the cus­tomer rather than the man­u­fac­turer.

The hall­mark, then, is the oldest form of con­sumer pro­tec­tion that exists, and the cur­rent Assay Office premises on Beulah Road at Hillsborough are known as Guardians’ Hall. But des­pite having almost 250 years of his­tory behind it, the office is a hi-tech sci­entific estab­lish­ment where hall­marks are just as likely to be applied (depend­ing on the item being assayed) by laser tech­no­logy as by the tra­di­tional hardened-steel dyes.

The tra­di­tional busi­ness of hall­mark­ing con­tin­ues to provide cus­tom­ers both nation­ally and world­wide with an assur­ance of qual­ity and purity. The instantly recog­nis­able Sheffield mark of the Yorkshire rose is care­fully applied to items of pre­cious metal which can range from the most del­ic­ate chain to a stun­ning one-off table centrepiece cre­ated by a con­tem­por­ary designer. Whatever the item, who­ever the cus­tomer, the inde­pend­ence and strin­gent stand­ards of The Sheffield Assay Office ensure accur­acy and inspire con­fid­ence.

© Sheffield Assay Office
© Sheffield Assay Office

The ori­ginal aim of the intro­duc­tion of hall­mark­ing was to pro­tect the public against fraud and the trader against unfair com­pet­i­tion. That prin­ciple is as import­ant in Sheffield in 2020 as it was when the first UK legis­la­tion relat­ing to hall­mark­ing was intro­duced in 1238.


You can find fur­ther read­ing on the his­tory and work of the Sheffield Assay Office on their own web­site:



A Life in Crime — Peter Stubbs — 17th Feb 2020

Peter Stubbs, who trav­elled from his home in Bakewell and was warmly wel­comed by an audi­ence of 48 mem­bers, is no stranger to Stumperlowe Probus Club. This was his fifth visit to us in just over two years.

Peter is a man of many parts, and tal­ents. On his first visit he man­aged to cram 900 years of legal his­tory into just over an hour. Then, after three talks on his other big pas­sion in life, naval his­tory, Peter rever­ted to the day job to enter­tain us with stor­ies of a selec­tion of the char­ac­ters — ran­ging from the col­our­ful to the scary — he rep­res­en­ted during his 35-year career as a crim­inal lawyer in Sheffield.

Peter Stubbs.            Photo ©

It was, as he poin­ted out in his intro­duc­tion, a story of his life in crime, not his life of crime. “My own crime record is modest,” he assured us. “I had a bit of a pen­chant for park­ing on yellow lines on shop­ping trips, and I also man­aged to pick up one or two speed­ing offences.

In my early 20s I was coming back from a night out in London, the fol­low­ing morn­ing, when an ‘Inspector Morse’ Jaguar over­took me and flagged me down, and in Sheffield many years later I was on Rivelin Valley Road when out jumped a police­man with a speed gun who told me I was doing 38mph just after the 40 limit had changed to 30.” The fact that he was on his way to work – in fact to York Crown Court — cut no ice with the zeal­ous officer.

Peter’s career began in 1978, and his prac­ti­cing cer­ti­fic­ate as a soli­citor was signed by Lord Denning, the Master of the Rolls for 20 years up to 1982 and one of the most famous names in British legal his­tory.

Although Peter’s prac­tice in Sheffield was a gen­eral one, a large pro­por­tion of his work was involved with crime. “It was inter­est­ing and at times excit­ing, and often quite fun,” he recalled. “But what I might think was fun was ser­i­ous busi­ness.”

Cases, per­haps not sur­pris­ingly in Sheffield, included hand­ling stolen scrap metal. Another reg­u­lar client had set up a bogus build­ing busi­ness and was caught steal­ing lead from the roof of a bay window. “It turned out they had done about 60 houses; he was found guilty and went to prison. He just accep­ted it as a hazard of the job.”

Petty crime often ran in fam­il­ies, who would be Peter’s cli­ents for ten years or more. He felt sorry for one lady, who was proud that one of her sons had reached the age of 16 without being ‘done,’ only to catch his broth­ers up with alarm­ing speed as he worked his way up the crim­inal ladder.

Today, all police inter­views must be recor­ded, with both sound and video, but it was not always the case. “In the old days, one of the officers would sit at the table taking notes, and it was not unknown for some of the evid­ence to be made up. Police are no dif­fer­ent to any­body else, and some­times they break the rules.”

The Police and Criminal Evidence Act has largely countered that, and today all evid­ence must be recor­ded.

Peter was acting for a man who had been accused of assault­ing a police officer one Friday night on Attercliffe Road, but for­tu­nately  for his client there were three people having an Indian meal by the window in a res­taur­ant who saw what happened and claimed that it was the police officer who assaul­ted the accused. They went to the police sta­tion, where the police did not take evid­ence but were obliged to pass the wit­nesses’ details on to Peter.

Peter recalled a lady called Violet, who would more appro­pri­ately have been called Violent, who lived in Attercliffe and was well known to police. She got into an argu­ment in a pub with a fellow cus­tomer who was not phys­ic­ally injured but dropped down dead with a heart attack. Violet was charged with threat­en­ing beha­viour, but later claimed that the invest­ig­at­ing officer had sexu­ally assaul­ted her. “I found that hard to believe, know­ing Violet, but she claimed to have evid­ence” (which turned out to be a sample of semen wrapped in cling film, which Peter felt duty bound to take home and store in his freezer).

The invest­ig­at­ing officer ran a defence of con­sent, which was accep­ted, although he was dis­missed because of unpro­fes­sional con­duct.”

Murder was all in a day’s work for Peter, and he gave us examples of some of his more mem­or­able cases. In the first, a hus­band had claimed that his wife had killed their daugh­ter and then tried to throw her­self under a bus. She was charged with murder, but an expert on pre-menstrual ten­sion gave evid­ence which res­ul­ted in the woman being com­mit­ted to a psy­chi­at­ric hos­pital.

Another client, a bus driver in Sheffield, had been arres­ted on sus­pi­cion of mur­der­ing his girl­friend, who was found dead with her throat cut on the floor of her flat at Park Hill. The only evid­ence against him was from the man’s aggrieved wife, who claimed that he had admit­ted to killing the victim. The accused was able to prove “beyond doubt,” accord­ing to Peter, that he was sev­eral miles away at the time of the murder, driv­ing his bus on the other side of Sheffield, but the jury found him guilty by 10 to two and he received a life sen­tence. The wife later admit­ted to Peter that she had lied, but an appeal was dis­missed and the bus driver died in prison four years later from a heart attack.

The last murder case involved a long stand­ing client, for whom Peter’s prac­tice had pre­vi­ously done con­vey­an­cing work, who told his part­ner that he had voices in his head telling him to kill people. She took him to hos­pital where they sought psy­chi­at­ric help, but they were sent on their way.

The fol­low­ing day the man con­fided to his wife: “Actually, the voices were telling me to kill you, but I didn’t want to tell you last night.” He later stabbed his part­ner 30 or 40 times and was charged with murder, although he offered a plea of man­slaughter which was accep­ted.

Peter roun­ded off his present­a­tion by taking ques­tions from the floor. One member asked if he watched TV detect­ive pro­grammes. “All the time,” he admit­ted. “I’m retired after 35 years, and I am watch­ing Inspector Morse! It’s ridicu­lous! But they are metic­u­lously done.”