Instrument pioneers in a very different West End

There was a time when not too far from the hustle and bustle of Selfridges, Harvey Nicks and Fortnum & Mason stood a fine scientific instrument supplier.

This advert, in an old HMSO Observer's Handbook, gives a no-nonsense list of what you'll find at No.122 Regent Street
This advert, in an old HMSO Observer’s Handbook, gives a no-nonsense list of what you’ll find at No.122 Regent Street

Negretti & Zambra, at No. 122 Regent Street and later at No. 15 New Bond Street, specialised in barometers and thermometers – everything you could need to set up a weather station. The brand among weather anoraks is the byword for quality. The company, along with Short & Mason, probably made the majority of barometers that adorn many hallway walls across Britain. Next time you visit old aunt Flo or uncle Albert chances are the barometer hung on the wall is made by one of these companies.

Enrico Negretti and Joseph Zambra started their company in 1850, which was run by them and their descendents until well after the Second World War. They had shops firstly in Regent Street and later at Holborn Viaduct. The company was highly successful, winning a medal at the Great Exhibition in 1851, counting among their customers the Astronomer Royal, Prince Albert, the Royal Observatory and Admiral Robert Fitzroy.

Initially they specialised in barometers and thermometers, particularly those needed for taking deep sea and atmospheric measurements, which until they arrived were very unreliable. Later they increased their range to include telescopes, gun sights, theodolites and optical instruments. During the Second World War Negretti expanded substantially to meet the demand for instruments for war planes in particular. Their  instruments were also produced under licence to supply the USAAF.

After their stand against Nazism in World War II, the two men helped found the United Nations. Churchill’s mother was American and he and FDR were distant cousins
After their stand against Nazism in World War II, the two men helped found the United Nations. Churchill’s mother was American and he and FDR were distant cousins

Go to No.122 Regent Street today and you’ll find a branch of the Body Shop. The shop at No.15 New Bond Street, which closed in 1975, 11 years after the company moved production to a factory in Aylesbury, is now a branch of watchmaker Patek Philippe. Outside you will find seated bronze statues of Allied wartime leaders Sir Winston Churchill and Franklin D. Roosevelt sharing a joke. The statue by Lawrence Holofcener was unveiled in 1995 by the Bond Street Association to mark 50 years of peace. I’m not sure how intentional this was but how fitting that they are outside Negretti’s old shop, the instruments of which played a big part in helping the Allies to prevail over the Axis.

Back in the day N&Z was highly regarded in the local community and people would phone to access data that the company compiled from its rooftop weather station. In the late 1950s it was the job of Geoffrey John Gill, an office junior who went on to become an apprentice draftsman, to collect these stats.

“I was getting tea, coffee and buns from a Greek cafe in Soho’s Wardor Street for the office staff, collecting the mail and using the franking machine and last but not least the holy of holy’ climbing to the shop roof top and collecting the charts from the sunshine glass ball recorder, the rain gauge, barograph and the hygrometer box. You see it was common in those days for people to phone N&Z to enquire what these readings had been for the past day or so, a typical quality N&Z service.” A full account of his time with the company can be found here.

Short and Mason were based in Walthamstow for nearly 60 years. They supplied instruments to the Polar expeditions of Scott and Shackleton
Short and Mason were based in Walthamstow for nearly 60 years. They supplied instruments to the Polar expeditions of Scott and Shackleton

Short & Mason were established five years prior to Negretti in 1845 by Thomas Short and James Mason. The business was located at 40 Hatton Garden, London, and produced precision measuring instruments including barometers, anemometers, and compasses. They became leaders in the field of barograph design and supplied scientific instruments for the Scott and Shackleton polar expeditions in the early 20th century and for Everest climbers.

In 1910 the company relocated to Macdonald Road, Walthamstow. It was here that 11 years later the company pioneered the theory that a storm forecast could be made from just observing the air pressure and whether it was rising or falling. The company went on to develop aeronautical, medical, meteorological and surveying instruments and were listed exhibitors at the British Industries Fair in 1922 and 1947.

In 1958 the business moved to Wood Street, Walthamstow, where it continued to trade until a merger in 1969 with Taylor Instrument Companies, of Leighton Buzzard, Beds. An account of somebody with experience of working for Short and Mason can be found here.

Many examples of Negretti & Zambra and Short & Mason instruments can be found on eBay and antique shops across the world, the finer examples often turn up at auction houses such as Bonhams where they go for thousands of pounds.

Though, like many industries, weather observing has become mostly automated there are are still probably hundreds of observers who still take the manual measurements every morning ‘because they can’. Though this observer relies on an automatic weather station for daily readings – there is nothing like the daily ritual of emptying the Snowdon raingauge or shaking down the maximum thermometer at 0900 GMT every day. One observer who still supplied the Met Office with monthly rainfall readings while in his 80s said that it was the one thing that got him out of bed every morning.

Examples of Negretti & Zambra instruments can be found on eBay
Examples of Negretti & Zambra instruments can be found on eBay

Perhaps it’s a little similar to the ever growing popularity of classic cars. A sense of being able to hold a piece of British engineering history that was so well designed that it still works today.

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Snow Survey of London (1946 – 2017)

I first wrote this blog in December 2013 not realising that the following winters were going to turn so mild. Winter 2013/14 ranks the worst of any winter I’ve studied in this area back to the snowy season of 1946/47. The following three winters ranked 53rd, 62nd and 42nd – the only ‘top 10’ winter for snowfall of the past 30 years was 2009/10!

Snow is a very rare commodity in lowland Great Britain – even rarer in the Home Counties, and in our part of east London. Pulling back the curtains on a cold winter’s morning to be greeted by a fresh fall of deep, crisp and even snow is something most children experience and hold dear for life. The slush, ice and chaos that inevitably follows all too quickly is forgotten.

OLYMPUS DIGITAL CAMERAMy memories of winters in the 1970s and 1980s is that they were far snowier and colder than they are today. But were they *always* cold and snowy? I decided to have a look back through the archives to find out. My first stop was the Met Office’s now defunct Snow Survey of Great Britain. This excellent compilation of reports logged by observers nationwide was printed annually as part of British Rainfall. But through lack of interest and cuts printing ceased after the 1991-92 season. Data continued to be collected though the modern version of the survey uses satellite technology to estimate daily UK snow depths – the spiel on the Met Office website tells us that this is far less subjective than an individual nipping out at 9am every morning to ‘stick in a ruler’ and, those within sight of high ground, to observe where the snow line is. Call me old fashioned but this is not very romantic and does a disservice to the hundreds of observers who down the years diligently logged all their information as objectively as possible. But on to the data…

Regional data was not included in the survey until the 1965-66 season. Though Wanstead isn’t listed I have taken an estimate from data supplied from stations at Eastcote (53m), East Barnet (70m), Charlton Park (46m), Twickenham (13m), Teddington (9m). Because this area is influenced by Thames streamer snowfall that blows in off the North Sea and is funnelled upriver I have also considered readings from Epping (107m), Rayleigh (73m) and Southend (27m). Indeed, in some years Wanstead’s snowfall is much more similar to Rayleigh and Southend than it is to Greenwich and Teddington. Though my site is only 18m it seems to catch the snow much better than surrounding areas – probably to do with the fact that Aldersbrook is surrounded by greenery. People walking down from Wanstead village often remark that Wanstead Park is far snowier than the village a couple of dozen metres or so higher. Before 1965 I have used data from Woburn, Bedfordshire, which at 89m and 40 miles away as the crow flies, is the closest station in that long running series.

The mean temperature of a winter can look cold but it doesn’t always tell the full story. You can have a winter dominated by high pressure over the near continent making things very dry. But the anticyclones that ridge from Central Europe to the Azores can leave us in the ‘warm’ part of the high – and often lead to days of anticyclonic gloom; cold grey, dank and boring weather with little sunshine. On paper a season can look cold but in reality totally unremarkable; it is the number of days with ‘snow lying’ that people remember. For snow to settle it needs to be cold! For this reason I haven’t bothered with ‘snow falling’ data as it can snow at 4C in very dry air – yet nothing settles. Most weather geeks find ‘snow falling’ the most frustrating when it doesn’t stick. So on to the results.

The Top 20 winters in Wanstead, using 'snow lying' and 'mean temperature' in stats. Click the image to view all 67 winters
The Top 20 winters in Wanstead, using ‘snow lying’ and ‘mean temperature’ in stats. Click here to view all 71 winters back to 1946/47

Once I worked out the ‘snow lying’ days I decided to devise a winter index by dividing ‘snow lying’ by seasonal mean temperature. Because the results using Celsius were problematic in that 1962/63 becomes very skewed upwards I decided to use Kelvin. The results are quite surprising. Coming out top, not surprisingly, is 1962-63 with an index of 25.2 and 69 days of snow lying. Second is 1946-47 with an index of 21.1. Third is 1981-82  with an index of 10.5 – surprisingly ahead of 1978/79, the first winter in the series that I can recall; I remember returning home from school one night in December 1978 and the snow being as deep as the twelve-inch step to our house.

The index of 25.2 for the 1962/63 winter and 21.1 for 1946/47 – over double the amount of 1981/82 – shows how ‘off the scale’ those two winters really were. My father, who doesn’t share my enthusiasm for the weather, can distinctly recall the severe conditions of 1962/63. He said the roads were so thick with snow that when the thaw finally arrived in March he’d become so used to driving on snow that he crashed through somebody’s front garden wall, after losing control of his Mini on surface water sat on the ice.

More recent winters, which pale by comparison, rank surprisingly highly. The 2009/10 winter comes in at Number 10, higher than the legendary 1986/87, where the coldest day in recent times was recorded in London, which came in at Number 12. It should be noted that January 1987, when on the 12th the temperature did not rise above -5.5C all day, was sandwiched by a mild December and February.

OLYMPUS DIGITAL CAMERASomebody asked me if it would snow and by how much over the next three months. The simple fact is I don’t know. While a predicted mean can look chilly on paper it is impossible to decipher how many peaks and troughs there will be. Just by looking at winters with a mean of, say, 5C doesn’t tell you much about snowfall. When you look at 1985-86 (mean 4.1C)  there were 22 days of snow lying at 9am – yet 2005/06 was colder (3.9C) and only 3 mornings saw snow lying – though that winter was particularly dry – the 13th driest in the series.

The median for ‘snow lying’ days in this series is six. The rolling median of the past 30 years, however, is only 2 so, with this in mind, if it does snow you should get out there and make the most of it.

You can view over 70 years of winters in this area, all ranked using my winter index here.

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*It should be noted that a day of ‘snow lying’ only qualifies if there is more than 50% cover at the observation time of 9am. This means that it could snow 1cm at 10am – if that snow thaws by 9am the next day it won’t count. Though 8 winters appear snowless it is possible that these winters did see temporary coverings

Will it be a White Christmas this year?

Will it be a white Christmas this year? It’s the question most forecasters get asked year after year as the big day looms less than a month away.

The snow probably won't arrive until after Christmas this year
The snow probably won’t arrive until after Christmas this year

It always fascinates me why Christmas and snow are so closely associated with each other when the odds, especially in London, are so stacked against it happening.

Perhaps it is the Christmas card scenes of Dickensian winters that get people yearning for the white stuff. Indeed, the image of snow covered cobbled streets can probably be blamed on Charles Dickens. The backdrop of A Christmas Carol, and a host of other books, were written when winters, and Yuletide, were generally much colder than they are now. Perhaps it was also the cold Decembers, which came during notably cold years as he was coming of age, that sowed the seed of his impressions of life in London. The Central England Temperature (CET)  for December 1829 and 1830 were 1.4C and 1.8C respectively. To give you perspective the average mean temperature for the Wanstead region in December is 5.6C. Of course we had a taste of what a Dickensian December was like three years ago in 2010 when the average mean temperature was 1.5C. Though bear in mind the mean for 2010 was 10.5C – way above the 8.2C and 8.7C mean temps of 1829 and 1830!

Christmas toys of yesteryear also took every opportunity to perpetuate the snow myth
Christmas toys of yesteryear also took every opportunity to perpetuate the snow myth

But back to this Christmas… First of all, what do we mean by a white Christmas? The definition used most widely – notably by the bookies – is for a single snowflake, even if it lands in the midst of heavy rain, to be observed falling in the 24 hours of 25 December at a specified location recognised by the Met Office. Interestingly, the Met Office uses weather observations from Gravesend-Broadness, some 12 miles away, to show current conditions in Wanstead. A lot, however, could be said by us weather anoraks about the different microclimates between here and south of the Thames.

Technically, there has not been a white Christmas in Wanstead for over 30 years. In 2010, we could still see the Christmas card Victorian snow scene in small patches of our gardens, but these were leftovers of a previous dump, so it doesn’t count. Frustratingly, there has been snow on several Boxing Days in Wanstead (1995 and 1996) and in the weeks running up to Christmas, but not on Christmas day itself. The most typical Wanstead Christmas day weather is mild and dry, although it has rained on 12 of the last 33 Christmas days.

So why does it often snow either side of Christmas but not on the actual day? For Wanstead, Christmas is at the beginning of the period when it’s likely to snow. Looking at climate history, wintry weather is more likely between January and March than December.

iced anemOn average, snow or sleet falls in the UK 5 days in December, compared with 7.6 days in January, 6.8 days in February and 6 days in March. White Christmases were more frequent in the 18th and 19th centuries, even more so before the change of calendar in 1752, which effectively brought Christmas back by 12 days. Climate change has also brought higher average temperatures over land and sea and this generally reduces the chances of a white Christmas.

For snow to fall we need moisture in the atmosphere. Snowflakes start their lives as ice crystals thousands of feet up, and when these tiny ice crystals collide they stick together in clouds to become snowflakes. If enough ice crystals stick together, they’ll become heavy enough to fall to the ground.

Precipitation falls as snow when the air temperature is below 2°C. It is a myth that it needs to be below zero to snow. In fact, in this country, the heaviest snowfalls tend to occur when the air temperature is between zero and 2°C. The falling snow does begin to melt as soon as the temperature rises above freezing, but as the melting process begins, the air around the snowflake is cooled. If the temperature is warmer than 2 °C then the snowflake will melt and fall as sleet rather than snow, and if it’s warmer still, it will be rain.

It sounds a simple combination, but getting precipitation on the days when there are temperatures low enough for snow are few and far between.

temple snowChristmas day in Wanstead, on the balance of probability and from previous patterns, is most likely to be a green and mostly cloudy but dry one. Some brightness is possible with temperature peaking at around 10°C. You can read my full methodology on why I think this may happen here.

Though my attempt to find the probability of a White Christmas effectively rules one out, there is still an outside chance that one could happen.

At this time of year the UK can effectively become a battleground between cold polar continental air to the north or east and moisture-laden mild tropical maritime air to the south and west. Where these air masses meet, snow is possible, but a lot depends on which air mass wins the battle. When battleground situations occur, in one location it can be snowing, but just 20 miles or so down the road it can be raining. This is because there is a fine line between the boundary of the warm and cold air.

There's nothing like an open coal fire. It's even better when it is cold enough outside to have one
There’s nothing like an open coal fire. It’s even better when it is cold enough outside to have one

In years gone by, Wanstead and the surrounding area has often ended up in the cold air mass or the warm air mass. In these situations dry and mild or dry and cold weather is often the result. Of course, in a cold air mass situation there is always the chance of showery activity of the North Sea. The weather so far this winter has not been anything out of the ordinary, so I’m afraid there is nothing to suggest a white Christmas is likely.

If it does turn very cold on December 24, pray for clouds to appear and we could be in with a chance. But at the end of the day we still need that vital combination of temperature and moisture. Snow, like Christmas in that sense, requires some magic.

Wanstead Weather – November 2013

Wanstead Weather – November 2013

November was colder than average with a mean temperature of 6.7C (1.2C below the 30-year average) – ranking it 69th in the series since 1881. Rainfall of 56.5mm was 99% of average – ranking it 61st in the series.

The month was just 0.04C cooler than last November – with 93% of the rain that fell in November 2012.

Air frosts: 4

Ground frosts: 9

Thunder: 1

Small hail: 1