"from the archives: poldhu and the marconi company during world war one", an evening...
TRANSCRIPT
School of somethingFACULTY OF OTHER
School of Philosophy, Religion, and History of ScienceFACULTY OF ARTS
From the archives: Poldhu and the Marconi Company during World War One
Elizabeth Bruton, Postdoctoral Researcher, “Innovating in Combat: Telecommunications and intellectual property in the First World War”University of Leeds and Museum of the History of Science, Oxford
Innovating in Combat• Elizabeth Bruton, Postdoctoral Researcher, “Innovating in Combat: Telecommunications and intellectual property in the First World War”
• Aim of the project is to help museums, archives, and the wider public to better appreciate the significance of communications technologies during World War One
• University of Leeds and Museum of the History of Science, Oxford
• Graeme Gooday and Elizabeth Bruton
• Funded by AHRC
School of Philosophy, Religion, and History of ScienceFACULTY OF ARTS
Outline of paper•Introduction•Poldhu and the Marconi Company up to World War One•Poldhu during World War One
• Commercial operation• Interception and
censorship• Wireless direction-
finding
•Conclusion•Questions?
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
Electrical engineer/inventor Guglielmo Marconi operating apparatus similar to
that used by him to transmit first wireless signal across Atlantic, 1901.
Copyright Life Magazine. Image licensed for personal non-commercial use.
Poldhu and the Marconi Company up to World War One
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
Marconi Wireless Station, Poldhu, c.1910.
Image available in the public domain via Wikimedia Commons
Poldhu during World War One
•Commercial usage•Allied communications•News (and propaganda?)•Interception and censorship•Wireless Direction-Finding
• Friend• Foe?
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
Wireless Direction-Finding Station on the East Coast of England during World War One.
Image available in the public domain.
Goniometer diagrams.
The name means 'angle measurer'. In radio context, it is a set of coils arranged to determine the bearing (direction) of a transmitter.
Image available in public domain via G1inf - Amateur Radio Station blog at http://g1inf.blogspot.co.uk/2009/11/what-is-goniometer.html
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
Technical Diagram of Bellini-Tosi Gonioneter (1907).
Image available in the public domain.
Diagrams of Bellini-Tosi direction-finding antennas.
The triangular loops at the top are the antennas, and the three two-turn coils at the bottom are simplified representation of the goniometer coils.
The operation of the system is straightforward. The sense coil ('S' in Fig.18, left) is rotated until a null (little or no output) is heard in the receiver. The sense coils are connected to a pointer, which indicates the direction of the source transmitter.
Image available in public domain via G1inf - Amateur Radio Station blog at http://g1inf.blogspot.co.uk/2009/11/what-is-goniometer.html
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
Inv. Num. 37692 – Bellini-Tosi Radiogoniometer, by Bellini & Tosi, Paris, c. 1907, Marconi Collection, Museum of the History of Science, University of Oxford.
This was an experimental instrument used by one of the makers, M. Bellini, for directive wireless transmission. Bellini and Tosi filed their British patent for the system in 1907, and the rights were bought by the Marconi company in 1912.
Image courtesy of the Museum of the History of Science, Oxford.
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
Inv. Num. 14937 - Bellini and Tosi Wireless Direction-Finder, 1907, Marconi Collection, Museum of the History of Science, University of Oxford.
This direction finder unit was made in 1907, the same year that the British patent was filed by the Bellini-Tosi for their system.
Image courtesy of the Museum of the History of Science, Oxford.
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
Diagram taken from Bellini and Tosi US Patent No. 943960 – “System of Directed Wireless Telegraphy”.
This was the first US patent applied for by Bellini and Tosi for their directive wireless system. It was applied for on 1 October 1907 and granted on 21 December 1909.
Image available in the public domain via Google Patent Search.
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
Bellini and Tosi system, 1912Working of Bellini and Tosi’s “directive wireless” system:
...their system utilised two static, orthogonal, vertical, triangular shaped [sic] antennas, the outputs of which were connected separately to two fixed, orthogonal, field coils. Reception of a signal by the antennas caused currents to flow through the coils to establish a magnetic field. This field was detected by a calibrated, rotating search coil, the output of which was connected to a receiver.The Bellini-Tosi system', pp.138-183 quoted in Burns, Russell W. Communications: An International History of the Formative Years. Vol. 32, IEE History of Technology Series. London: Institution of Electrical Engineers, 2004, 419.
Marconi engineer H.J. Round (1920) on the Bellini and Tosi system:The Bellini-Tosi idea was so complete that one might say that all the work after the original conception consisted in carrying out correctly the idea and in the improvement of the receiving apparatus. The sensitiveness of the crystal, although greater than either the magnetic or electrolytic detectors, still limited the ranges of reception very greatly on directional aerials.Round, H. J. "Direction and Position Finding." Journal of the Institution of Electrical Engineers 58, no. 289 (1920), 229.
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
Inv. Num. 20815 - Marconi Bellini-Tosi Direction Finder, by Marconi Company, London, c. 1916, Marconi Collection, Museum of the History of Science, University of Oxford.
This was used to detect the position of enemy wireless stations using direction finding equipment and a signal triangulation method. This system was used by the Royal Navy and British Army to trace the position of German submarines, surface naval vessels, and Zeppelins.
Image courtesy of the Museum of the History of Science, Oxford.
Map of routes of Zeppelins made by Marconi Direction Finding operators on the east coast of England, 1916, Marconi Archives, Bodleian Library, University of Oxford.Image courtesy of Bodleian Library, Oxford.
School of Philosophy, Religion, and the History of ScienceFACULTY OF ARTS
Thank you!
http://blogs.mhs.ox.ac.uk/innovatingincombat/
@WWITelecomms / @lizbruton
School of Philosophy, Religion, and History of ScienceFACULTY OF ARTS