Wednesday, 22 October 2014

A bit of moaning in the Mercury

So -  the Mercury isn't happy with the state of Greenwich - it says

"For some years past the town of Greenwich, although the central one of the three which constitutes this great Borough, has been steadily sinking into a state of decay.  The depression has, at length, become so manifest, in the form of empty houses and diminished trade that everybody who has an interest of any kind in the place is anxiously enquiring whether something cannot be done towards a recovery of its lost position and a restoration of its former prosperity.   Deptford, which ten  or twelve years ago used to excite the sympathy of the people of Greenwich by its impoverished  state, its heavy taxes, its silent wharves and its deserted streets, is now thronged with a bustling, cheerful, thriving population while poor Greenwich  half the day long is as stirless in its scenes as Salisbury plain. 
The silence in it is only broken at intervals by the sepulchral sound of the wheels of an empty omnibus wending its solitary way to Deptford and the Kent Road  to pick up  a few passengers for the West end.   Even if you see some active pedestrian approaching the public baths for having nothing else to do, his melancholy countenance renders it doubtful whether he is about to enter for the purposes of ablution or to drown himself, in consequence of the dullness that reigns in the town. 
Woolwich, it seems, is equally prosperous with Deptford and from a like cause- the activity in its government establishments. Scarcely a house in either town is empty; while on many streets in East Greenwich there are more houses to be let than there are houses occupied.
Kentish and Surrey Mercury  27th November 1858
The reason behind the article can be found in diagram below:

Drawing thanks to Chris Grabham

Sunday, 19 October 2014

From Elektron to 'e'' Commerce

AND ALSO - more about submarine cables.   Here is the front cover of Stewart Ash's book on submarine cables - where there will be a lots about Greenwich

-- read the book   ----------------------------  theres more to come -------------

Transatlantic telecommunications timeline

WITH work on the Enderby Wharf project in our minds we hope to publish here various items about the history of telecommunications in Greenwich.   BUT to start with, as a bit of general background, here is a timeline of transatlantic telecommunications generally.  You will have to wait to find out where Greenwich fits into all this ......................

Timeline of Transatlantic Telecommunications

1600 William Gilbert publishes De Maqnete (On Magnets)

1794 Visual semaphore telegraph established between Paris and Lille

1796 First visual semaphore telegraphs established in the UK

1820 Hans Oersted discovers electromagnetic field due to electric current

1821 Andre Ampere establishes the elementary laws of electrodynamics

1826 Georg Ohm defines basic electrical law V=IR

1831 Michael Faraday discovers electromagnetic induction

1837 Cooke and Wheatstone patent the 5 needle electric telegraph

1838 Alphabetic code of dots and dashes developed by Alfred Vail for Samuel Morse

1839 5 needle electric telegraph established between London Paddinqton and West Drayton

1842 Joseph Henry discovers oscillatory nature of a suddeelectrical discharge

1843 William Montgomerie introduces Malayan gutta-percha to the UK ( used as insulation for submarine cables)

1850 - Lord Kelvin defines relationship between resistance, inductance and capacitance of an oscillatory circuit  
Pierre Guitard observes 'coherence' of dust particles in air when electrified
Proposal that a telegraph cable could run between St Johns Newfoundland and Ireland to connect old and new world

1851 - submarine telegraph cable laid between Dover and Cap Gris Nez
Heinrich Ruhmkorff invents the induction coil

1852 -Michael Faraday announces theory of electric and magnetic 'lines of force' - submarine cable laid between Portpatrick (Scotland) and Donaghadee (Ireland)

1853 Lt Maury USN surveys sea bed from Newfoundland to Ireland finding a plateau suitable for laying submarine cable

1854 The American entrepreneur Cyrus Field initiates the project to lay a telegraph cable from USA to Ireland

1855 -Lord Kelvin calculates that speed of signalling through a cable is inversely proportional to the square of the cable length
Charles Bright surveys Irish coast and selects Valentia Bay as cable landing point for a submarine cable

1856 Cyrus Field forms the Atlantic Telegraph Company

1857  HMS Cyclops surveys the great circle line Newfoundland to Ireland and confirms Lt Maury's findings 
8 August USS Niagara and HMS Agammemnon attempt initial cable lay Ireland to USA but cable breaks on 11 August after 400 miles laid in depths up to 2.5 miles

1858  First transatlantic telegraph cable completed (but fails after 3 weeks due to insulation breakdown) Lord Kelvin develops the mirror galvanometer

1864 Maxwell publishes paper 'A Dynamical Theory of the Electromagnetic Field' detailing mathematical formulas for the propagation of electromagnetic waves

1866-First successful transatlantic telegraph cable laid by the 'Great Eastern' supervised by Lord Kelvin - American dentist Mahlon Loomis discovers elementary radio telegraphy by sending on-off signals 22km across Blue Ridge mountains using a kite to pick up static electricity as energy source

1872 Loomis awarded US Patent 129971 for his 'aerial telegraph system' but fails to turn his discovery into commercial success.

1873 Maxwell formulates theory that electromagnetic waves are of the same nature as light with similar characteristics

1874 Emile Baudot develops the 5 unit telegraph code

1876 Alexander Graham Bell submits telephone patents.

1888  Heinrich Hertz experiments prove existence of electromagnetic waves as predicted by Maxwell. Oliver Lodge identifies importance of 'resonance' between oscillatory circuits to optimise energy transfer leading to the principle of selective tuning which he called syntony

1891 Eduard Branly constructs the 'coherer' for detecting electromagnetic waves (cohesion of iron filings contained in a glass tube when exposed to electromagnetic waves, and hence their decrease in resistance to a current flowing through them from Latin 'cohaere' = stick together

1892 William Crookes predicts 'telegraphy without wires'
First Strowger automatic telephone exchange operates in Indiana USA

1894 Oliver Lodge transmits 'Hertzian' waves over 60m during lecture to British Association for Advancement of Science using a modified Branly coherer

1895 In Italy Marconi transmits 'Hertzian' waves some 2-3km using elevated aerial and an earth connection
In Russia Aleksandr Popov demonstrates reception of signals over 60m using lightening conductor as an aerial and a Branly -Lodge coherer.

1896 Marconi obtains patent for wireless telegraph

1897 -Marconi demonstrates radio link from Lavernock Point near Cardiff 14km across Bristol Channel
Marconi establishes the 'Wireless and Signal Company Ltd' later to become the 'Marconi Company

1899 Michael Pupin proposes adding induction (loading) coils to cables to extend transmission distances

1901 Marconi transmits Morse letter 'S' across Atlantic from Poldhu Cornwall to Signal Hill, Newfoundland
Canadian Reginald Fessenden patents radiotelephony

1902 Oliver Heaviside and Arthur Kennely predict ionised layer in upper atmosphere

1903 Marconi Poldhu - Cape Cod radio link provides limited commercial telegraphy (mainly used by newspapers)
Fessenden transmits speech using modulated arc over 20km

1904 John Ambrose Fleming invents the thermionic diode
Fessenden demonstrates radiotelephony over 40km in USA

1905 Fessenden invents the superheterodyne circuit

1906  -Lee de Forest adds third electrode to the diode to create the 'audion' (triode) thermionic valve
Fessenden broadcasts gramophone records to ships over distance of 80km probably the worlds first radio broadcast

1907 Marconi establishes limited public radio telegraph service between UK and USA via Canada

1912 Alexander Meissner develop s the electronic HF generator

1914 Marconi experiments with valve transmitters for British navy

 1915  New York-San Francisco cable uses telephone amplifiers
first transatlantic radio broadcast Arlington Virginia to Paris usin 3kW transmitter with over 300 thermionic valves

1922 Regular sound broadcasting commences in the UK

1924 Edward Appleton demonstrates existence of the ionosphere
Marconi and Franklin exploit skywave transmission via  ionosphere over distance of 4000km

1926 Canada-UK radiotelephone service commences

1927 USA - UK radiotelephone service commences

1935 Armstrong demonstrates frequency modulated system

1937 Alec Reeves invents pulse code modulation

1943 Submarine coaxial telephone cable using submerged valve amplifiers laid between Anglesey and Isle of Man

1944 Werner von Braun develops V2 rocket at Peenemunde Germany- forerunner of USA launch vehicles for their space programme

1945 Arthur C. Clarke publishes article in Wireless World proposing placing man-made satellites in geostationary orbit to act as extraterrestrial relay stations to provide worldwide radio coverage

1947 Transistor invented at Bell Labs by Bardeen, Shockley and Brattain

1950 Key  West-Havana submarine coaxial telephone cable laid

1954 US Navy reflects voice messages off the moon

1956 TAT 1 the first UK-USA/Canada transatlantic telephony coaxial cable with submerged repeaters completed

1957 USSR launches first man-made satellite (Sputnik 1) with a 96 minute, 229/946km elliptical orbit

1958 -USA satellite Explorer 1 confirms existence of the Van Allen belts
US Air Force satellite SCORE tested as active repeater recording incoming messages on tape then retransmitting them

1959 Laser is invented

1960 -Aluminized plastic balloon ECHO 1 launched by USA at altitude of 1600m to act as passive reflector of radio signal - ECHO 2 tests reflected transmission between USA and France

1962 -Telstar active satellite is launched by USA - telephony and TV tests between USA and UK France commence
Joseph Licklider of MIT suggests a network of interconnected computers to provide rapid data access ( origin of the INTERNET

1964 SYNCOM satellite is launched into geostationary orbit

1965 INTELSAT 1 geostationary satellite commences commercial satellite communications

1966 Kao and Hockham of STC Laboratories propose optical telecommunications through pure glass fibres

1969 US Defense Department creates ARPANET (advanced research projects agency network) using packet transmission and switching (routing) which eventually develops into the INTERNET

1979 Analogue cellular mobile radio telephony commences in Japan

1980 Commercial optical fibre link Brownhills-Walsall in UK goes into service

1987 First long distance submarine optical fibre links Corsica and French mainland

1988 TAT 8 first transatlantic optical fibre cable completed

 1990 Tim Berners-Lee working at CERN devises the World Wide Web operating over the INTERNET

1991 Digital mobile cellular radio GSM commences in Finland

2000 Transatlantic optical fibre cable 360 Atlantic with capacity of nearly 2 Terabits/s commences operation (1 terabit = 1012 bits/s )
This list was given to us and it is understood it was part of a conference pack in 2007 - we do not have details..  If that is not so, and if it is your list, and your copyright, then please email ( and it will be removed from this site, with an apology - or remain with a note from you.


Thursday, 16 October 2014