TheNational Physical Laboratory (NPL) is the nationalmeasurement standards laboratory of the United Kingdom. It sets and maintains physical standards for British industry.
Founded in 1900, the NPL is one of the oldestmetrology institutes in the world.Research and development work at the laboratory has contributed to the advancement of many disciplines of science, including the development of early computers in the late 1940s and 1950s, construction of the first accurateatomic clock in 1955, and the invention and first implementation ofpacket switching in the 1960s, which is today one of the fundamental technologies of theInternet. The former heads of NPL include many individuals who were pillars of the British scientific establishment.[2][3]
In the 19th century, theKew Observatory was run by self-funded devotees of science. In the early 1850s, the observatory began charging fees for testing meteorological instruments and other scientific equipment. Asuniversities in the United Kingdom created and expandedphysics departments, the governing committee of the observatory became increasingly dominated by paid university physicists in the last two decades of the nineteenth century. By this time, instrument-testing was the observatory's main role. Physicists sought the establishment of a state-funded scientific institution for testing electrical standards.[4]
The Electricity Division of the National Physical Laboratory in 1944
The National Physical Laboratory was established in 1900 atBushy House inTeddington. Its purpose was "for standardising and verifying instruments, for testing materials, and for the determination of physical constants".[5] The laboratory was run by the UK government, with members of staff being part ofthe civil service. It grew to fill a large selection of buildings on the Teddington site.[6]
Administration of NPL was contracted out in 1995 under a Government Owned Contractor Operated (GOCO) model, via a new operating company, NPL Management Ltd.Serco won the bid and all staff transferred to their employment. Under this regime, overhead costs halved, third-party revenues grew by 16% per annum, and the number of peer-reviewed research papers published doubled.[7][8]
The new laboratory building, which had been maintained by Serco, was transferred back to theDTI in 2004 after the private sector companies involved made losses of over £100M.[9]
It was decided in 2012 to change the operating model for NPL from 2014 onwards to include academic partners and to establish a postgraduate teaching institute on site.[10] The date of the changeover was later postponed for a year.[11] The candidates for lead academic partner were the Universities ofEdinburgh,Southampton,Strathclyde andSurrey[12] with an alliance of the Universities of Strathclyde and Surrey chosen as preferred partners.[13]
Funding was announced in January 2013 for a new £25M Advanced Metrology Laboratory that will be built on the footprint of an existing unused building.[14][15]
Alan Turing, known for his work at theGovernment Code and Cypher School (GC&CS) atBletchley Park during theSecond World War to decipher German encrypted messages, worked at the National Physical Laboratory from 1945 to 1947.[20] He designed there theACE (Automatic Computing Engine), which was one of the first designs for a stored-program computer. Clifford Hodge also worked there and was engaged in research on semiconductors. Others who have spent time at NPL includeRobert Watson-Watt, generally considered the inventor of radar, Oswald Kubaschewski, the father of computational materialsthermodynamics and thenumerical analystJames Wilkinson.[21]
The first accurate atomic clock, acaesium standard based on a certain transition of thecaesium-133 atom, was built byLouis Essen and Jack Parry in 1955 at NPL.[25][26] Calibration of the caesium standard atomic clock was carried out by the use of the astronomical time scaleephemeris time (ET).[27] This led to the internationally agreed definition of the latestSI second being based on atomic time.[28]
NPL has undertaken pioneering computer research since the mid-1940s.[29][30][31] From 1945,Alan Turing led the design of theAutomatic Computing Engine (ACE) computer.[32] The ACE project was overambitious and floundered, leading to Turing's departure.[33]Donald Davies took the project over and concentrated on delivering the less ambitiousPilot ACE computer, which first worked in May 1950. Among those who worked on the project was American computer pioneerHarry Huskey. A commercial spin-off,DEUCE was manufactured byEnglish Electric Computers and became one of the best-selling machines of the 1950s.[33]
Beginning in the mid-1960s,Donald Davies invented and pioneered the implementation ofpacket switching, now the dominant basis for data communications incomputer networks worldwide.[34] Davies designed and proposed a national commercial data network in his 1965Proposal for the Development of a National Communications Service for On-line Data Processing.[35] Subsequently, the NPL team, led byRoger Scantlebury, were the first to implement packet switching in the local-areaNPL network in early 1969,[36][37][38][39] which operated until 1986. They carried out work to simulate the performance of a wide-area packet-switched network capable of providing data communications to most of the U.K.[40] Their research and practice influenced theARPANET in the United States, the forerunner of theInternet, and other researchers in the UK and Europe, includingLouis Pouzin, as well as in Japan.[41][42][43]
NPLinternetworking research was led by Davies, Derek Barber and Scantlebury, who were members of theInternational Network Working Group (INWG).[48][49] They observed that connecting heterogeneous computer networks creates a "basic dilemma" since a common host protocol would require restructuring the existing networks. To study this, NPL connected with theEuropean Informatics Network (Barber directed the project and Scantlebury led the UK technical contribution)[50][51][52] by translating between two different host protocols; that is, using agateway. Concurrently, the NPL connection to the Post OfficeExperimental Packet Switched Service used a common host protocol in both networks. NPL research confirmed establishing a common host protocol would be more reliable and efficient.[53] The EIN protocol helped to launch the proposed INWG standard.[54]Bob Kahn andVint Cerf acknowledged Davies and Scantlebury in their 1974 paper "A Protocol for Packet Network Intercommunication".[55] Barber was involved in Internet design discussions in 1980.[56]
Scrapbook was an information storage and retrieval system that went live in mid-1971. It included what would now be calledword processing,e-mail andhypertext, anticipating many elements of theWorld Wide Web.[57][58] The project was managed by David Yates who said of it "We had a community of bright people that were interested in new things, they were good fodder for a system like Scrapbook" and "When we had more than one Scrapbook system, hyperlinks could go across the network without the user knowing what was happening".[57][59] It was decided that any commercial development of Scrapbook should be left to industry and it was licensed to Triad and then to BT who marketed it as Milepost and developed a transaction processor as an additional feature. Various implementations were marketed onDEC,IBM andITL machines. All NPL implementations of Scrapbook were closed down in 1984.[60]
Derek Barber proposed a network mail protocol and implemented it on theEIN in 1979, the first European implementation ofelectronic mail.[61][62]Jon Postel referenced Barber's work in his first paper on Internet email, published in theInternet Experiment Note series.[63]
In the early 1990s, the NPL developed three formal specifications of theMAA: one inZ,[64] one inLOTOS,[65] and one inVDM.[66][67] The VDM specification became part of the 1992 revision of the International Standard 8731–2, and three implementations inC,Miranda, andModula-2.[68]
A 2020 study by researchers fromQueen Mary University of London and NPL successfully used microwaves to measure blood-based molecules known to be influenced by dehydration.[69]
The National Timing Centre (NTC) Programme has been developed to provide a time infrastructure system for research and technology.[73] In 2025, £68 million was awarded to the National Physical Laboratory to further develop the NTC.[74]
^Clarke, Roger (29 January 2004)."Origins and Nature of the Internet in Australia".www.rogerclarke.com. Retrieved23 February 2020.Much of the history of computing has been written by Americans. ... More balanced histories reflect the fact that, for all of the U.S.A.'s dominance from about 1950, the early developments occurred on both sides of the Atlantic
^Scantlebury, Roger (2001).A Brief History of the NPL Network. Symposium of the Institution of Analysts & Programmers 2001. Archived fromthe original on 7 August 2003. Retrieved13 June 2024.The system first went 'live' early in 1969
^John S, Quarterman; Josiah C, Hoskins (1986)."Notable computer networks".Communications of the ACM.29 (10):932–971.doi:10.1145/6617.6618.S2CID25341056.The first packet-switching network was implemented at the National Physical Laboratories in the United Kingdom. It was quickly followed by the ARPANET in 1969.
^Haughney Dare-Bryan, Christine (22 June 2023).Computer Freaks (Podcast). Chapter Two: In the Air. Inc. Magazine. 35:55 minutes in.Leonard Kleinrock: Donald Davies ... did make a single node packet switch before ARPA did
^Clarke, Peter (1982).Packet and circuit-switched data networks(PDF) (PhD thesis). Department of Electrical Engineering, Imperial College of Science and Technology, University of London. Archived fromthe original(PDF) on 3 August 2022. Retrieved4 June 2024. "As well as the packet switched network actually built at NPL for communication between their local computing facilities, some simulation experiments have been performed on larger networks. A summary of this work is reported in [69]. The work was carried out to investigate networks of a size capable of providing data communications facilities to most of the U.K. ... Experiments were then carried out using a method of flow control devised by Davies [70] called 'isarithmic' flow control. ... The simulation work carried out at NPL has, in many respects, been more realistic than most of the ARPA network theoretical studies."
^Needham, Roger M. (2002)."Donald Watts Davies, C.B.E. 7 June 1924 – 28 May 2000".Biographical Memoirs of Fellows of the Royal Society.48:87–96.doi:10.1098/rsbm.2002.0006.ISSN0080-4606.S2CID72835589.This was the start of 10 years of pioneering work at the NPL in packet switching. ... At that lecture he first became aware that Paul Baran, of the RAND Corporation, had proposed a similar system in the context of military communication. His report was not as detailed as Davies's design and had not been acted on.
^"Smithsonian Oral and Video Histories: Vinton Cerf".National Museum of American History.Smithsonian Institution. 24 April 1990. Retrieved23 September 2019.Roger Scantlebury was one of the major players. And Donald Davies who ran, at least he was superintendent of the information systems division or something like that. I absolutely had a lot of interaction with NPL at the time. They in fact came to the ICCC 72 and they had been coming to previous meetings of what is now called Datacomm. Its first incarnation was a long title having to do with the analysis and optimization of computer communication networks, or something like that. This started in late 1969, I think, was when the first meeting happened in Pine Hill, Georgia. I didn't go to that one, but I went to the next one that was at Stanford, I think. That's where I met Scantlebury, I believe, for the first time. Then I had a lot more interaction with him. I would come to the UK fairly regularly, partly for IFIP or INWG reasons
^Cerf, V.; Kahn, R. (1974)."A Protocol for Packet Network Intercommunication"(PDF).IEEE Transactions on Communications.22 (5):637–648.doi:10.1109/TCOM.1974.1092259.ISSN1558-0857.The authors wish to thank a number of colleagues for helpful comments during early discussions of international network protocols, especially R. Metcalfe, R. Scantlebury, D. Walden, and H. Zimmerman; D. Davies and L. Pouzin who constructively commented on the fragmentation and accounting issues; and S. Crocker who commented on the creation and destruction of associations.
^abWard, Mark (5 February 2010),Alan Turing and the Ace computer, BBC News,archived from the original on 10 October 2021, retrieved17 February 2021 "it is certainly the first system I know of to combine screen-based word processing, hypertext and e-mail as a service over a general-purpose computer network."
^Scrapbook and the umbrella (groupware from the 70's), Retro Computing Forum, 11 February 2021,archived from the original on 10 October 2021, retrieved18 February 2021 which citesYates, David M. (1997),Turing's Legacy: A History of Computing at the National Physical Laboratory 1945–1995, Science Museum,ISBN978-0901805942
^Barber, D., and J. Laws, "A Basic Mail Scheme for EIN," INWG 192, February 1979.
^Lai, M. K. F. (1991). A Formal Interpretation of the MAA Standard in Z (NPL Report DITC 184/91). Teddington, Middlesex, UK: National Physical Laboratory.
^Parkin, Graeme I.; O’Neill, G. (1990). Specification of the MAA Standard in VDM (NPL Report DITC 160/90). National Physical Laboratory, Teddington, Middlesex, UK.
^Parkin, Graeme I.; O’Neill, G. (1991). Prehn, Søren; Toetenel, W. J. (eds.).Specification of the MAA Standard in VDM. Formal Software Development – Proceedings (Volume 1) of the 4th International Symposium of VDM Europe (VDM’91), Noordwijkerhout, The Netherlands. Lecture Notes in Computer Science. Vol. 551. Springer. pp. 526–544.doi:10.1007/3-540-54834-3_31.
^Lampard, R. P. (1991). An Implementation of MAA from a VDM Specification (NPL Technical Memorandum DITC 50/91). Teddington, Middlesex, UK: National Physical Laboratory.
^Minelli, C. & Clifford, C.A. (2012). "The role of metrology and the UK National Physical Laboratory in Nanotechnology".Nanotechnology Perceptions.8:59–75.{{cite journal}}: CS1 maint: multiple names: authors list (link)
Campbell-Kelly, Martin (1987). "Data Communications at the National Physical Laboratory (1965-1975)".Annals of the History of Computing.9 (3/4):221–247.doi:10.1109/MAHC.1987.10023.ISSN0164-1239.S2CID8172150.
