The Early Development of the British Underground Trunk Telephone Network

NOTES AND REFERENCES

• D.G. Tucker, 'The First Cross-Channel Telephone Cable: the London-Paris Telephone Links of 1891', Trans. Newco men Soc., 47, 1977, 117–132.
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• A.E. Kennelly, 'High-frequency Telephone Circuit Tests', Electrician, 54, 1904, 433–6; Bela Gati, 'On the Measurement of the Constants of Telephone Lines', ibid. 58, 1906, 81–2; B.S. Cohen and G.M. Shepherd, 'Telephonic Transmission Measurements', J.Inst.Elect.Engrs., 39, 1907, 503–565; B.S. Cohen, 'Standard Cable Measurements', P.O. Elect. Engrs. J., 6, 1913–14, 1–20.
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• B.S. Cohen and J.G. Hill, 'Long distance and cable telephony', P.O.Elect.Engrs.J., 9, 1916–17, 135–155.
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• D.G. Tucker, 'Beginnings of the Telephone Service', Proc. Inst. Ele ct.Engrs., 123, 1976, 561–8.
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• A. Pearson, manuscript report dated 6 July 1882, with conclusions by W.H. Preece, Post Office Records Office (hereafter P.O.R.O.), Preece collection.
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• F.G.C Baldwin, The History of the Telephone in the United Kingdom, London, 1938 (1st edition 1924), 179.
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• Baldwin, op.cit., 185; J.T. L., 'An early cable experiment', P.O. Ele ct. En grs.J., 8, 1915–16, 118–122.
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• Baldwin, op.cit., 186–7.
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• Baldwin, op.cit., 188–9.
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• F.L. Rhodes, Beginnings of Telephony, Harper, New York, 1929, 100–126.
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• Most of the information in this section comes from Baldwin, op.cit., 319–323, and Rhodes, op.cit., 128–9.
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• Engineer-in-Chief's report, 31/3/1897, P.O.R.O., ref. POST 76/15.
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• P.M.G.'s Minutess, Vol.597, 1896, item no.17233, P.O.R.O.
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• 'The Post Office London-Birmingham Underground Telephone Cable', Electrician, 42, 1899, 465–7.
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• P.M.G.'s Minutes, Vol.751, 1903, item no.1459, P.O.R.O.
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• E in C's report, 31/3/1901, P.O.R.O., ref.POST 76/15.
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• J. Gavey, Inaugural Address, J. Inst. Elect. Engrs., 36, 1906, 4–35.
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• P.M.G.'s Minutes, Vol.638, 1898, item no.15015, P.O.R.O.
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• E in C.'s report 31/3/1900, P.O.R.O., ref. POST 76/15.
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• Details of this procedure were given by Sir W. Noble, 'The Long-distance Telephone System of the United Kingdom', J.Inst.Elect.Engrs., 59, 1921, 389–406, see especially pp.391–2.
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• K.D. Mayne, 'Heaviside's Communication Cable Designs', Electronics & Power, 23, 1977, 710–11.
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• A.H. Roberts and W.J. Hilyer, 'Combined Telephone and Telegraph cables: Important Trials', P.O. E7ect.Engrs.J., 13, 1920–21, 29–48.
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• J. Gavey, op.cit., 32.
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• F. Scowen, 'Some Notes on the Early History of Loading of Cables', Papers presented at the second weekend meeting on the History of Electrical Engineering, Inst.Elect.Engrs., 1974, 11/1–11/4.
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• J.E. Brittain, 'The Introduction of the Loading Coil: George A. Campbell and Michael I. Pupin, Technology and Culture, 11, 1970, 36–57.
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• As ref. 1.
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• M.L Pupin, 'Wave Propagation over Non-uniform Electrical Conductors', Trans.Amer.Math.Soc., 1, 1900, 259–286.
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• G.A. Campbell, 'On Loaded Lines in Telephonic Transmission', Phil.Mag., 6th series, Vol.5, 1903, 313–330 + plates.
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• M.D. Fagen (ed.), A History of Engineering and Science in the Bell System, Bell Telephone Labs., 1975.
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• H.V. Hayes, 'Loaded Telephone Lines in Practice', paper read at St. Louis, U.S.A., reprinted in Electrician, 54, 1904, 362–5.
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• F. Dolezalek and A. Ebeling, 'Experiments in Long-distance Telephony on the Pupin System', Electrician, 50, 1903, 722–3 and 817–9 (reprinted and translated from Elektrotechnische Zeitschrift).
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• It seems fairly clear that the Post Office refused to discuss the matter with Siemens, taking the line that the British patents on loading were not valid anyway; see P.M.G.'s Minutes Vol.751, 1903, item no.1459, P.O.R.O.
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• W.G. Radley, 'Fifty Years' Development in Telephone and Telegraph Transmission in Relation to the Work of Heaviside', Heaviside Centenary Volume, Inst.Elect.Engrs., 1950, 76–89.
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• J. Gavey, discussion on paper by B.S. Cohen and G.M. Shepherd, J.Inst.Elect.Engrs., 39, 1907, 541.
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• E. in C.'s report, 31/3/1903, P.O.R.O., ref. POST 76/15.
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• Baldwin, op.cit,. p.667.
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• E. in C's report, 31/3/1905, P.O.R.O., ref. POST 76/16.
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• J. Gavey, Inaugural address, J.Inst.Elect.Engrs., 36, 1906, 33.
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• Baldwin, op.cit., 464.
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• W. A. J. O'Meara, 'Submarine Cables for Long-distance Telephone Circuits', J. Inst. Elect. Engrs., 46, 1910–11, 309–356. (On pp.329–330, O'Meara quotes some subjective speech tests on the cable which seem to suggest an improvement of about 17dB; but I believe this applies to the circuit looped back on itself so that the true figure is 8.5dB. In any case, the method is suspect.)
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• P.O.R.O. file E 5534/1912, ref. POST 30/2203. In this file the P.M.G. states the rate of increase in trunk calls to be over 12 per cent per year.
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• E. in C.'s report, 31/3/1912, P.O.R.O., ref. POST 76/18.
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• E. in C.'s report, 31/3/1914, ibid.
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• P.O.R.O. file E 5745/1916/VI, ref. POST 30/3617.
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• P.O.R.O. ref. POST 86/49.
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• W.J. Hilyer, 'London-Birmingham-Liverpool Telephone Cable', P.O. Elect. Engrs. J., 7, 1914–15, 32–40; J.G.'London-Birmingham Loaded Cable: Results Obtained in the Final Tests', ibid, 8, 1915–16, 206–212; J.G. H (ill), ’London-Birmingham-Liverpool Loaded Cable: Results Obtained in the Final Tests of the Birmingham-Liverpool Section', ibid, 9, 1916–17, 130–4; J.G.'BirminghamSheffield Loaded Telephone Cable: Results Obtained in the Final Tests', ibid, 211–12.
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• Based on Appendix C of E. in C.'s report, 31/3/1917, P.O.R.O., ref. POST 76/20.
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• B.S. Cohen and J.G. Hill, 'Long Distance and Cable Telephony' P.O.Elect.Engrs.J., 9, 1916–17, 1–21 and 135–155, especially p.13.
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• S.A. Pollock, 'Balancing of Telephone Cables which Require to be Loaded for Superimposed Working', P.O.Elect.Engrs.J, 7, 1914–15, 41–66 and 357–366; J.G. Hill, Telephonic Transmission, London, 1920; J.G. Hill, 'Phantom Telephone Circuits.....', J.Inst.Elect.Engrs., 60, 1922, 675–705; E. Mallett, Telegraphy and Telephony, London, 1929.
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• See, for example, footnote to 'List of Trunks and Junctions, 1908', P.O.R.O., ref. POST 86/45.
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• The early history of phantom circuits is rather complicated. The first disclosure of the principle was probably the patent by Black and Rosebrugh (Brit.Pat.1477 of 16 April 1879). The history given by F.L. Rhodes, Beginnings of Telephony, Harper, New York, 1929, 189–195, is useful but not entirely accurate. A history of the main developments is given by R.D. Law, The Development of Phantom Circuits in Telephony'. Papers Presented at the Meeting on the History of Electrical Engineering, July 1977. Inst of Electrical Engineers, 13/1–13/6.
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• 'List of Trunks and Junctions, 1900', P.O.R.O., ref. POST 86/43; ditto, 1911, ref. POST 86/46.
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• B.S. Cohen and J.G. Hill, 'Long Distance and Cable Telephony', P.O.Elect.Engrs.J., 9, 1916–17, 1–21 and 135–155, quotation from p. 13.
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• F. Tremain, 'The Design and Use of Telephone and Telegraph Cables', J.Inst.Elect.Engrs., 41, 1908, 713–735. especially p.729.
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• Much of this paragraph is based on W. Noble, 'The Long-distance Telephone System of the United Kingdom', J.Inst.Elect.Engrs., 59, 1921, 389–406.
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• T. Shaw, The Conquest of Distance by Wire Telephony', Bell System Tech.J., 23, 1944, 337–421.
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• Electronic devices, particularly in the form of the thermionic diode and triode, had been available for over a decade, but it took all that time to develop techniques to the point where reliable amplifiers were available. See, for example, P. Dunsheath, A History of Electrical Engineering, London, 1962.
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• W. Noble, op.cit.
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• E. in C's report, 31/3/1920, P.O.R.O., ref. POST 76/21.
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• Information extracted from E. in C.'s report, 31/3/1923, Appendix E2, P.O.R.O., ref. POST 76/22.
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• W. Cruickshank, 'Telegraphy and Telephony, 1929-31', J.Inst.E7ect.Engrs., 70, 1931–2, 153–163.
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• Ibid.
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• E. in C's report, 31/3/1921, P.O.R.O., ref. POST 76/21. Note that the W.E.Co. became Standard Telephones and Cables Ltd. in 1925, and this company and G.E.C. remained the only firms supplying telephone repeaters in the U.K. until about 1935.
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• Several early accounts are readily available, e.g. A.B. Hart, Telephone Repeaters, Inst. of P.O. Elect. Engrs., Professional Paper No.75, 1918; A.B. H(art), 'The Telephone Repeater', P.O.Elect.Engrs.J., 12, 1919–20, pp.1–1, 70–75, 129–133 and 210–6; J.G. Hill, Telephonic Transmission, London, 1920, Ch.14; J.A. Cooper, 'Telephonic Repeaters and Long Distance Telephony, J. Inst.Elect.Engrs., 61, 1922, 75–80; and early text-books such as W.L. Everitt, Communication Engineering, McGraw-Hill, New York, 1937, 317–322.
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• Personal experience of the author.
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• R.M. Chamney, 'Modern Telephone Trunk lines', P.O.Llect.Engrs.J., 25, 1932–33, 282.
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• C Robinson and R.M. Chamney, Recent Research Work on Telephone Repeaters, Inst.P.O.Elect.Engrs., Professional Paper No. 99, 1924.
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• British Patent 29165 of 1913.
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• British Patents 18018 of 1913 (balancing network for two-wire repeaters) and 142, 115 (filters for two-wire repeaters).
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• The whole story can be found in P.O.R.O. file of Minute 12777/1922. A technical account of the principles involved is given in C. Robinson and R.M. Chamney, Four-Wire Telephonic Repeater Systems, Inst. P.O.Elect.Engrs., Professional Paper No. 83, 1921.
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• Some descriptions of repeater stations were published, e.g. A.B. H(art), 'A Modern Telephone Repeater Station', P.O.Elect.Engrs.J., 18, 1925–26, 260–290; and R.J. Nunn, 'The Aldeburgh Telephone Repeater Station', ibid, 352–8. For details of circuits, facilities, etc., see A.B. H(art), 'The London-Glasgow Trunk Telephone Cable and its Repeater Stations', ibid. 19, 1926–27, 103–148.
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• H.S. Black, 'Stabilized Feedback Amplifiers', Bell System Tech.J., 13, 1934, 1–18 or Electrical Engr. (U.S.A.), 53, 1934, 114–120.
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• For a general account see D.G. Tucker, 'The Early History of Amplitude Modulation, Sidebands, and Frequency-division-multiplex', Radio and Electronic Engr., 41, 1971, 43–7.
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