Negretti & Zambra – A History Part Two

Part 2 – The Concluding Years

Welcome to the concluding part on my history of the company of Negretti & Zambra and thank you first of all for the positive response to part one of the history. If you missed it, it can be found though the following link.

Negretti & Zambra - A History (Part One)

The initial story took us from the birth of the founders and their Italian roots through to their meteoric first decade of trading including their appearance at The Great Exhibition of 1851. The concluding years is perhaps a difficult title given that the company remained trading for many years after but we begin in 1860. 

The 1860’s hailed in a vast period of expansion for the company. It first moved from 11 Hatton Garden to larger premises at 1 Hatton Garden after having already acquired additional premises at Cornhill in 1857. Later in the decade, the redevelopment of Holborn and Hatton Garden into what would become Holborn Viaduct demanded a further move to a brand new building at number 38 Holborn Viaduct. The grand opening of the new area in 1869 was attended by their patron, Queen Victoria and their premises were right at the heart of the proceedings. Earlier in 1862 they also purchased the business of the London instrument maker, John Newman whose premises at 122 Regent Street provided the company with a prestigious flagship store in the heart of London. Newman himself was a very well respected maker of meteorological instruments, he provided instruments to Darwin for his voyage on HMS Beagle with Admiral Fitzroy and his famous station barometer was replicated, improved and sold by Negretti & Zambra for many years following his death in 1860, and the subsequent purchase of his business two years later.

Figure 1 – Negretti & Zambra’s London Premises

Figure 2 – A Newman Type Station Barometer by Negretti & Zambra of the 1860’s in my possession.

The year of the Regent Street opening also coincided with the second large scale exhibition in which Negretti & Zambra took part. Like its predecessor, the 1862 International Exhibition had large purpose built premises for the occasion. Located in South Kensington on a site which is now occupied by The Natural History Museum it opened in May 1862 and housed some thirty thousand exhibitors. Negretti & Zambra’s first entry was allocated to, “Class XIII – Philosophical Instruments & Processes Depending on their Use” and as before, the company was surrounded by some of the finest instrument makers of the period. Names such as Casella, JB Dancer, De Grave Short & Fanner, Elliott Brothers, J Hicks, Pastorelli, Pillischer, Smith Beck & Beck, Breguet, EG Wood & Naudet were all In attendance.

With the rising popularity of photography and Negretti & Zambra’s position at the Crystal Palace it seems obvious that the company would seek to present themselves in regard to this new medium and as such they were also entered into Class XIV – Photography & Photographic Apparatus. During the exhibition, Henry Negretti also undertook experiments with aerial photography conducting a balloon flight in Sydenham to an altitude of 4000 feet with a specially adapted darkroom for use in the air. The daring feat thus proved that aerial photography was indeed possible and I suspect the carefully coordinated timing did much to publicise their attendance at the Exhibition.

Both of their exhibits were successful in achieving a prize medal, the first for “Meteorological instruments. For many important inventions and improvements, together with accuracy and excellence in objects exhibited” and the second for “Beauty and excellence of photographic transparencies and adaption of photography to book illustrations etc.”

Shown below is an example of the 1862 International Exhibition Prize medal awarded to Negretti & Zambra. This example is one which I was lucky enough to purchase and was awarded to the famous scale-makers, De Grave, Short & Fanner who exhibited alongside the company.

Figure 3a & 3b – The 1862 International Exhibition Prize Medal

Negretti’s interest in ballooning was most likely sparked by the pioneering balloonist and Superintendent of Meteorology at The Royal Observatory, James Glaisher who conducted flights between 1862 and 1866, the memoirs of which were finally published in a book, “Travels in Air”. It is not known whether Glaisher accompanied Negretti on his flight but the company certainly provided aneroid barometers for experimentation purposes. Glaisher later wrote that,

“A third aneroid graduated down to five inches read the same as the mercurial barometer throughout the high ascent to seven miles on September 5th 1862. I have taken this instrument up with me in every subsequent high ascent.”

Figure 4 – James Glaisher & Henry Tracey Coxwell in 1864

The mid-point of the 1860’s was peppered with disruption for Negretti & Zambra with the building of Holborn Viaduct and their eventual move in the final year of the decade to new premises but the company still found time to complete one of their most influential publications. “The Treatise on Meteorological Instruments”

Figure 5a & 5b – The Treatise on Meteorological Instruments by Negretti & Zambra. 1864

Like its predecessor, the publication was meant to be both catalogue and educational transcript. The instruments displayed within the catalogue are of course those manufactured by the company but they also include thermometers emblazoned with “Casella patent” proving that the company had agreed the rights with Casella to both sell and advertise his instruments. Interestingly, some of the instruments in this publication still also continue to be signed to H. Negretti & Zambra with others simply Negretti & Zambra. A minor point but useful for dating such transitional instruments as they are discovered. What is perhaps more appropriate to this “Treatise” is that its focus specifically on meteorological instruments allowing the company to provide a much deeper and authoritative explanation of the tools associated with the practice of meteorology, a specialism which had been and remained the company’s stronghold for most of its existence. (If you would like to read this book in more detail, please see my book section for details).

The first half of the 1870’s continued to be a period of invention for the company and a further three patents for thermometers were lodged with The Patent Office between 1873 & 1874. The practical uses of the barometer were also keenly considered by the company. A mining barometer was readily advertised and must have been a successful product given the Government guidance provided in 1872 after the discovery that a change in pressure was always recorded prior to a mine explosion. The Mines (Coal) Regulations Act of 1872 stated that, “after dangerous gas has been found in any mine, a barometer and thermometer shall be placed above ground in a conspicuous position near the entrance of the mine.”

Agricultural use for the barometer was also given consideration and a Farmer’s barometer was produced which incorporated a more scientifically accurate hygrometer. Their catalogue states:

“For ascertaining the humidity of the atmosphere, the general character of the weather, and the approach of wind and rain. The Farmer’s barometer combines three distinct instruments – the Barometer, The Thermometer and the Hygrometer, and is equally valuable to the Agriculturist and the Invalid, a difference of 5 to 8 degrees being considered a healthy amount of moisture in the air of dwelling rooms.

Hitherto, the use of scientific instruments of this class has been confined to very few observers, and until lately has borne very little fruit. Nevertheless, through the instrumentality of James Glaisher Esq, FRS, as Secretary of The British Meteorological Society, multitudes of observations have been taken with extreme accuracy, and duly registered; and it is from these carefully collected data that we are enabled in a measure to interpret the various changes that we feel and see going on in our atmosphere.”

The quote is interesting in that it shows the company’s continual development and refinement of the barometer to make it relevant for specific scenarios, the continual efforts to make the reading of the barometer more accessible and also how closely the company were affiliated with the scientific elite. You will remember James Glaisher from his earlier use of Negretti & Zambra aneroid barometers during his pioneering balloon flights and also the deep sea thermometers that Admiral Fitzroy supported. A new and improved double bulb example of the latter was developed and specifically employed during the early 1870’s by The Royal Society’s Challenger Expedition. At that time, it was considered one of the most scientifically fruitful exploratory missions to have taken place for centuries.

The aneroid barometer also saw some developments during this period. The aspiration for self-recording instruments was a function that had already been given close attention by Negretti & Zambra in relation to thermometers during their earlier career and following the development of pocket aneroid barometers, it was perhaps the next and most obvious development was to devise some way for the readings to be recorded without continuous and close attention by the observer.

The company were also responsible for the invention of the “Self-Recording Aneroid Barometer” as it became known. The result was a large cased instrument which included a fusee pendulum clock and a large aneroid barometer. To the centre of the instrument was provided a large brass drum which included a paper graph and a pen. All three elements were closely connected, the clock drove the drum and also regulated the intermittent engagement of the pen to the graph. It also enabled a small tap which was applied to the barometer prior to the pen’s engagement and ensured the barometer was reading correctly. The barometer itself was connected to the pen arm and would regulate the pen movement in line with the pressure reading on the barometer which would then be transferred to the graph. 

What I am explaining is of course the first appearance of what we now commonly consider to be the barograph. In more modern instruments the clock was changed and placed within the drum so that it could move under its own power and this enabled the reduction in size to take place. However efficient, the barograph is neither more technically interesting or aesthetically pleasing than these early examples and the catalogues of Negretti & Zambra, Casella, Hicks, JH steward and others all advertised these instruments widely for a period of about ten years. It was of course the development of the barograph that ultimately led to this instruments demise but the latter would never have existed without this very clever piece of engineering.

Figure 6a & 6b – A Negretti & Zambra and a JH Steward Self-Recording Aneroid Barometer.

From 1875 the final half of the decade was largely consumed by the numerous world fairs that continued to be held after the initial success of the 1851 Exhibition. Their catalogue of the 1880’s proudly advertised a prize medal for “Optical & Physical Instruments” from the 1875 Santiago Exhibition in Chile. A year later, three prize medals at The Philadelphia Exhibition for, “Meteorological Instruments, Thermometers and Microscopes” and a further Gold Medal at the 1878 Paris Exhibition for Meteorological Instruments. They did however still find time to lodge two further patents in 1876 for hydrometers and in 1877 for thermometers and hygrometers.

After the huge successes of the preceding thirty years, 1879 was a solemn year for the company. On the 27th of September, the founding partner, Henry Negretti sadly died from acute lung infection. His son HPJ Negretti seems however to have been involved in the company for some time prior to his Father’s death and alongside Joseph Warren Zambra and his son JC Zambra, a new partnership was agreed.

Thankfully, the loss of Henry Negretti did not spell the company’s demise and they continued to enjoy the patronage of the scientific community, Governmental Departments and Royalty alike. The RNLI also continued their affiliation and in the early 1880’s a decision was made to furnish mariners and fishermen with an aneroid barometer that would be suitable for use aboard small vessels and more importantly be affordable to those with a modest income. The reason for this decision was much the same as was intended with the original Storm stick barometer but these small, more portable and much hardier instruments would allow mariners to foretell inclement weather whilst at sea. Both Negretti & Zambra and Dollond were commissioned to manufacture these so called Fisherman’s aneroid barometers and Negretti continued to make them for the RNLI and for general sale for another fifty years or more. The design is simple and yet it resulted in one of the most pleasing and sought after aneroid barometers which are still loved by collectors to this day.

Figure 7 – An RNLI Fisherman’s Aneroid Barometer by Negretti & Zambra

Another similarly aesthetic barometer was also developed during the early part of the decade, the long range glycerine and mercury barometer was intended to allow for more precise reading of atmospheric pressure by using an extended scale. It was described as follows:

“The Long range or open scale barometer consists of a glass tube of the syphon form; one side of the syphon A (or closed end), being about 33.5 inches long, and the other only a few inches in length. To this short end is joined a length of glass tubing B, of a much smaller internal diameter; both tubes are of equal length, the smaller one being open at the top. The large tube A, is filled with quick silver, and the small tube B is partly filled with glycerine, a fluid many times lighter in specific gravity than quicksilver; the rising and falling of the quicksilver column in the large tube having a lighter fluid to balance, and that dispersed over a larger space by reason of the difference in the diameter of the two tubes, a longer range is obtained due to the unequal capacity of the two tubes and the difference in the specific gravity of quick silver and glycerine.

The range of these barometers is from six to ten inches to the inch of an ordinary barometer. A hundredth of an inch can easily be observed without the use of a Vernier. It is a most interesting instrument, as from the extremely extended scale the slightest variation is plainly visible. The actual size and form is about that of an ordinary barometer”. 

These examples are rarely encountered so it is likely that they were only produced in small numbers. They are so aesthetically pleasing that they were probably aimed at the domestic market as a means to avoiding the complications of using a Vernier, however I suspect for that reason alone they were not considered serious enough by the more scientific user. It is perhaps one of the few examples where the scientific ingenuity of the company perhaps failed to capture the market by trying to appeal to two different audiences.

Figure 8a & 8b – Two examples of The Negretti & Zambra Glycerine & Mercury Long Range Barometer

The exhibition calendar of course remained full for the company during the 1880’s although thankfully more close to home in the main. There were Fisheries Exhibitions in Norwich, Edinburgh and London between 1881 and 1883 for which numerous prize medals were awarded and the International Health Exhibition in 1884 for which the company’s thermometers remained a firm favourite with the judges. The most unusual and farthest reaching of all of their exhibition history was the Java Exhibition in 1883 although a gold medal for their optical instruments was perhaps enough solace for the distances involved.

In 1888, the remaining founder Joseph Warren Zambra retired and his other son MW Zambra joined his brother JC Zambra and HPJ Negretti to create a new partnership, although just four years later JC Zambra died, pre-deceasing his Father by five years. Given the numerous management shifts and final loss of both founding partners it is perhaps forgivable that the 1890’s seemed a rather sparse period for Negretti & Zambra in regards to inventiveness. That is not to suggest that the company were any less successful, a fact made clear by the company’s purchase of property in Islington at Half Moon Crescent in 1901 which was used as a means to consolidate its manufacturing base. The proceeding demolition of the site and the erecting of new buildings would by 1911 eventually become the famous, Half Moon Works which served the company for many years to come. 

The company endured the First World War and were employed throughout by the Ministry of Munitions providing instruments for military use. Their involvement with the development of early aviation instruments was also to prove significant for the company’s direction in later years.

To prove that they had not lost its focus on the development of meteorological instruments, perhaps their most popular patent was lodged in 1915 for the company’s new weather forecasting suite of products. Negretti & Zambra had spent most of its history attempting to make weather instruments more accessible to the domestic audience for obvious business reasoning and the new forecasting products which allowed a user to interpret air pressure and wind direction into a reasonably accurate forecast at a moment’s notice was simply ground breaking and effectively demystified the often confusing movements of the barometer needle.

The suite of products ranged from large travel sets including a forecasting aneroid barometer and large desk type forecaster to small pocket aneroid versions and even simple ivorine forecaster discs or standalone desktop versions could be used in conjunction with any pocket or wall aneroid barometer. The range therefore suited every different pocket and was wildly popular in the post war climate when it eventually found its feet. It was perhaps the last of the Negretti & Zambra barometer developments that really broke the mould for the domestic market before the onset of radio weather forecasts and it began to publish its own weather forecasts using the product in its London stores. Examples of these products remain hugely popular with collectors who wish to take a more analogue and hands on approach to weather prediction and appreciate the superb craftsmanship of these weather instruments.

Figures 9 a, b, c, d – Various examples of Negretti & Zambra’s Weather Forecasting products

The 1920’s also saw a renewal of the Negretti & Zambra catalogue. The new format had a decidedly different feel to its predecessor which reflects the radical developments in printing and publishing that had taken place in the intervening years. The M2 catalogue of Standard Meteorological Instruments as it first appeared in the 1920’s presented a slimming down of its voluminous Victorian product range. Whether that was purely down to company focus or lack of third party supply in a post war environment is not clear but it does introduce aviation instrumentation and some more industrial type products which clearly show a diversion away from high street retailing. Gone are the informative explanations of yester year so it must be assumed that the company expected their customers to be better informed or of an already scientific leaning. 

Further management transition happened during this period, HPJ Negretti died in 1919 and G. Zambra retired two years later in 1921. The firm however still managed to maintain family ownership and HN Negretti, PE Negretti & MW Zambra extended the partnership structure of the founders. MW Zambra finally retired in 1936 leaving the Negretti family in sole charge of the company.  The M3 catalogue was also released in the 1930’s in a very similar format and with much the same content.

As is evident from their new catalogues, the First World War brought about a greater leaning of its focus to industry rather than retail. Instruments continued to be made for public consumption but aviation and industrial markets were likely to have been more lucrative. This change was further compounded during the Second World War with the destruction of their Holborn Viaduct premises during Luftwaffe raids in May 1941.

Figure 10 – Image showing the aftermath of the Luftwaffe Raid at Holborn Viaduct

The premises were sadly never rebuilt and the company moved its Head Office to the existing premises at 122 Regent Street which had both office space and a retail premises at street level.

The retail premises were not the only Negretti & Zambra buildings to suffer during the war and their Half Moon Works also sustained bomb damage whilst carrying out work for the Government. This event led the company to occupy a safer temporary works in Chesterfield where they were set to work in manufacturing various gauges and thermometers for use in RAF planes. This works did not remain after the war due to the distances involved but an aviation factory was set up in Chobham to continue to service that industry.

The end of the war also saw the death of HN Negretti in 1945 and three years later, the company was incorporated into a Limited Company with the Negretti family maintaining majority ownership. The post war era saw an upturn in Negretti & Zambra’s fortunes and a new manufacturing site was purchased in Stocklake, Aylesbury where a housing estate was also constructed for its employees. Expansion overseas also saw sites crop up in Holland, South Africa, Canada & Australia.

The 1940’s saw the last of the large format catalogues that the company produced and the M4 also displayed a new Negretti & Zambra triangular shaped logo. The catalogue again remains largely the same as its Twentieth Century predecessors but gone are the aviation instruments. This feature is perhaps not surprising given that the company was by this point slowly drifting into two distinct arms of business, one serving aviation which would eventually become Negretti Aviation and the other manufacturing its historic catalogue. The company did however publish a rather unusual small book entitled, “Scientific Facts & Data”. It was unusual in the sense that The United Kingdom had declared war with Germany just two months prior to its publication and also that it is simply a glossary of meteorological terms with associated facts and explanations including such random facts as the temperature of various warm and cold blooded animals. This attempt was perhaps not quite as instructive as their previous attempts.

Figure 11a – The Negretti & Zambra M Series Catalogues

Figure 11b – A story of Temperature Measurement and Scientific Facts & Data by Negretti & Zambra

The last formal publication from the company was entitled, “A Story of Temperature Measurement”. It is an informative historical work although it seems to have been published as an interesting aside for customers rather than as a sales generating tool. The book only stretches to twenty pages and provides a good summary for the reader, surprisingly the first mention of their products comes on page eighteen but six of their thermometers are referenced and provide some good insight into the design styles of that period.

The Mid Sixties heralded the company’s almost entire removal from London which had been planned since the creation of the Aylesbury site and the long transition included the re-housing of workers and their families who wished to continue to work for the firm. The Half Moon works was closed and demolished and the flagship premises at 122 Regent Street closed its doors for the final time in 1965. A smaller retail outlet was opened at 15 New Bond Street and an opticians business at 15C Clifford Street but it is not clear how long these premises remained operational beyond that point. The instrument business for which this article is mainly concerned really ceased to exist by 1980 when this part of the company was sold off to the British Rototherm Company and the Negretti family finally ceased its long association with the company at this point.

The Negretti & Zambra Group thereafter continued to supply industry and aviation but continued on a slow process of decline thereafter. The business was sold off to Meggitt PLC and the name was changed to Meggitt Aviation in 1993 and the remaining automation arm of the business was sold off and finally succumbed to failure in the year 2000. A rather ignominious end to this most famous instrument making company.

It could be said that the change in focus to industry was the correct move in the unsteady and changing environment of the early Twentieth Century but it ultimately led to their final demise. We will never know whether changing tastes of retail consumers would also have promoted the same conclusion in the Post War environment however what remains of the company’s Victorian and Early Twentieth Century heyday are some of the finest and accurate instruments from that period and continue to provide pleasure to collectors across the globe.

The year 2000 completes the story of this historic company and I hope you have enjoyed reading both articles. As mentioned, if you have missed earlier episodes, they will be retained on my website at the following link

As ever, I would be very pleased to have your feedback and if you have any further questions or indeed suggestions for the next article, please feel free to get in touch.

Kind Regards


Jason Clarke Antiques

(+44) 07815 046645



Sources & Further Reading for Part 1 & Part 2:

Encyclopaedic Illustrated & Descriptive Catalogue by Negretti & Zambra – Various years

Treatise on Meteorological Instruments by Negretti & Zambra (1864)

Centenary 1850 – 1950 by Negretti & Zambra (1950)

The Italian Influence on English Barometers from 1780 by Edwin Banfield (1993)

King of the Clinicals – The Life and Times of JJ Hicks (1837 – 1916) by Anita McConnell (1998)

Barographs by Philip R Collins (2nd Edition 2021)

Fitzroy & His Barometers by Philip R Collins (2007)

Negretti & Zambra - A Potted History 1850 to 2000 by David Day (Publish date unknown)

Scientific Facts & Data by Negretti & Zambra (1940)

A Story of Temperature Measurement by Negretti & Zambra (1958)

Various Negretti & Zambra ephemera collected by the author.



Hi Jason,
Part 2 concluding the era of NZ very interesting its a deep research into their manufacturing business. Furthermore this famous family was a major meteorological instruments producer and I being a keen weather hobbyist I had the preveledge to order instruments during the 1970’s .Many of the instruments are still in use at my private station and in my NZ museum .Thank you Jason and your Newman mercury barometer a collector piece.

Edley Michaud March 16, 2024

I served the last two years of my student apprenticeship with N&Z at Half Moon Crescent between about August 1961 and June 1964. I was a ‘Sandwich’ degree student at City University in Instrument and Control engineering. They sponsored me at university and I was a full time employee, for which I remain very grateful. My first six months with the company were in the laboratory on the second floor of the main building. The lab was managed by Fred Greening who was a rather kindly, gentle, but reclusive manager. The day to day work being supervised by a character who was the absolute opposite of those charactersistics, and of whom the least said the better.

He took an instant dislike to me because of a previous turbulent history of which he had been apprised.

Fortunately the other technical staff were a wonderful group with whom it was a pleasure to work.They took me under their wing and I learned a great deal. A memorable person was Derek Hemmings who came to work every day on a Vincent 1000. He amused us with stories of fire watching during the war.

My second apprenticeship period at N&Z was in the workshop of the Aviation Department under foreman Fred Blow. Here I received an excellent training which stood me in good stead all my life. The craftsmen were wonderfully helpful and a pleasure to work with. A highlight of my experience was being given a batch of ejection seat permissive devices for the Folland Gnat which governed the minimum height for safe firing. What a responsibility! A low point was making a pressure test cell with a perspex window fir one of the engineers. I gave it a highly polished finish, which Fred regarded with horror and told me to take it back and give it a machined finish!

After graduating in the Summer of 1963 I then worked again in the Aviation Department Design Office under David Conway….. until June 1964 when I moved away to Manchester. I worked on the fuel control system for the Concorde’s Bristol Olympus engines, under contract to H M Hobson. An amusing story was that a large bleed valve was being shipped to Hobson by rail. But on the Caledonian Road en route to Euston the crate was stolen off the back of an open truck stopped at a traffic light. When the thieves found it contained just a hunk of stainless steel, they threw it in the Regent Canal. The explanations to Hobson for the delay must have been hilarious.

David was a ‘super’ supervisor, one of the best I had in the next 40 years, and I had many excellent ones. He drove a Triumph Roadster with a dickey seat in the boot.

While I was in Manchester David moved on to Aviation Electric in Montréal. I discovered this in 1966 when we were also moving to Canada. He met us at Dorval Airport and took us out for a meal downtown before we went to a hotel.

I spent my following career in the nuclear industry in Canada becoming chief engineer of one of the world’s largest nuclear power stations [2000 Mwe] a good deal of my success I ascribe to my training at N&Z.

During retirement I worked on the restoration of Handley Page Halifax ay the RCAF Museum and was amused to find that the fuel system and carburation for the Bristol Hercules engines were supplied by H M Hobson. My first assignment was to restore the autopilot which was a classic pneumatic/mechanical device designed in the 1940s. My training was useful in this.

The foreman of the restoration disliked engineers and managers on principle and with a passion, as both being absolutely useless. So, it was a mistake to have shown him my business card of ‘Engineering Manager’ when I volunteered. But the autopilot would lead on to more and more ambitious projects over the next 8 years. At the end he asked me how an engineer and manager happened to have so many practical skills and I was only too happy to tell him what an N&Z apprenticeship could do for you.

About 10 years ago I found David in the Montréal directory and spoke. He was still alive and kicking, married to a French-Canadian lady.

Although I was grateful for the training I received from wonderful people, I could see that the company was really doomed through lack of investment and a forward looking technically competent senior management. Most of the modern machinery that did exist was wartime American materiel probably paid for by the government to expedite defence production. The rest were Victorian antiques.

When I arrived and asked who was running the company I was told rather respectfully that it was Peter and Paul Negretti [Mr Peter and Mr Paul] who woukd arrive once a year at Half Moon Crescent in chauffeur-driven Rolls for a visit. I don’t know if this was correct because I never saw them.

I once asked an older technician who was working full time on a pneumatic capsule weighbridge concept [on behalf of a retired technical director] if he had heard of strain gauges. He looked at me blankly! I was only 20 and could see that the approach was likely a complete waste of money.

So I’m sorry to hear that things went badly after I left. But not really surprised.

Thank you for your work.

Rod Clarke June 26, 2023

Great investigation work
Thank you Jason

Edley April 15, 2023


Michael crook March 26, 2022

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