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BRASS BASE SINGLE CORE CABLE, 1900's
Single core Telegraphy cable with steel armour for under ground use.
Insulation may be Gutta Percha.
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A0573
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SINGLE CORE ARMORED CABLE, 1900's
Early under ground or under water telegraphy cable.
Insulation may be Gutta Percha. Gutta percha was obtained from a variety of guttiferous trees throughout the Pacific Rim although different varieties produce materials of differing quality. The differences generally reflect the quantity of resin in the product with that from Pahang having the lowest resin content. Balata has one of the highest resin contents and was obtained from trees in the tropical regions of South America.
There is much confusion in the literature, and amongst collectors, as to “what gutta percha is”. In practical terms, and when addressing collectors’ items, the material is probably the whole residue from the latex, dried after collection from whichever tree was its source. This material tends to range from dark yellow through red to black. It is possible that it has undergone some degree of purification but, given the variations in initial composition, it would be extremely difficult to confirm this, even by detailed chemical analysis.
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A0571
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SAMPLE OF CABLE LAID BY GREAT EASTERN, 1865
The transatlantic telegraph cable was the first cable used for telegraph communications laid across the floor of the Atlantic Ocean. It crossed from the Telegraph Field, Foilhommerum Bay, Valentia Island, in western Ireland to Heart's Content in eastern Newfoundland.
The transatlantic cable bridged North America and Europe, and expedited communication between the two. Whereas it would normally take at least ten days to deliver a message by ship, it now took a matter of minutes by telegraph.
Five attempts to lay it were made over a nine-year period—in 1857, two in 1858, in 1865, and in 1866—before lasting connections were finally achieved by the SS Great Eastern captained by Sir James Anderson with the 1866 cable and the repaired 1865 cable. Additional cables were laid between Foilhommerum and Heart's Content in 1873, 1874, 1880 and 1894. By the end of the 19th century, British-, French-, German- and American-owned cables linked Europe and North America in a sophisticated web of telegraphic communications.
The sample is held together by three steel wires wrapped around it
Nortel Collection
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A1317
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CENTRE SECTION OF 1st TRANSATLANTIC CABLE, 1860's
The transatlantic telegraph cable was the first cable used for telegraph communications laid across the floor of the Atlantic Ocean. It crossed from the Telegraph Field, Foilhommerum Bay, Valentia Island, in western Ireland to Heart's Content in eastern Newfoundland.
The transatlantic cable bridged North America and Europe, and expedited communication between the two. Whereas it would normally take at least ten days to deliver a message by ship, it now took a matter of minutes by telegraph.
Five attempts to lay it were made over a nine-year period—in 1857, two in 1858, in 1865, and in 1866—before lasting connections were finally achieved by the SS Great Eastern captained by Sir James Anderson with the 1866 cable and the repaired 1865 cable. Additional cables were laid between Foilhommerum and Heart's Content in 1873, 1874, 1880 and 1894. By the end of the 19th century, British-, French-, German- and American-owned cables linked Europe and North America in a sophisticated web of telegraphic communications.
A card Attached Reads: "A scrap- the centre portion of the first Atlantic Cable ever thought to be laid and this was I believe ???in laying of common coatingsand coverings wre used - bringing the full cable up to a large size= but this shows the wires.C.E.N. has kept this from about the time of laying - but which year- cannot now say." C.E.N. refers to C.E.Neate who died in 1907 and was Mr H.G.W. Reilly's Grandfather. Donated by H.G.W.O'Reilly ITT Business Systems - Private Communications Division Maidstone Sidcup Kent.
Nortel Collection
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A1316
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COHERER DEMONSTRATION BOARD, 1920's
The first radio transmissions were made using a spark transmitter and a receiver known as a “Coherer”.
In 1890 Edouard Branley found that if high frequency oscillating currents were passed through a series of metal fillings in a glass tube, the fillings tended to coherer and become more conducting.
Without the influence of the radio frequency currents, the fillings passed very little current.
Later this arrangement gave place to a device called a crystal detector
The coherer was a primitive form of radio signal detector used in the late nineteenth and early twentieth centuries, consisting of a capsule of metal filings in the space between two electrodes.
It was a key enabling technology for radio, and was the first device used to detect radio signals in practical spark gap transmitter wireless telegraphy. Its operation is based upon the large resistance offered to the passage of electric current by loose metal filings being decreased under the influence of radio frequency alternating current.
The coherer became the basis for radio reception around 1900, and remained in widespread use for about ten years. The coherer saw commercial use again in the mid 20th century in a few primitive radio-controlled toys that used spark-gap transmitter controllers.
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A1284
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FOOT COMMUTATOR KEY, 1930's
Polarity reversing key known as a "Commutator Key".
Used with Double plate sounder item A0227 and Wheatstone needle item A0228.
Would be operated by the foot.
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A0237
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TRANSATLANTIC CABLE IN PENDANT AND LETTER, 1866
Detail of Letter
"Mr Cowburn, Thanks for the trouble you have taken regarding the piece of Submarine Cable. It's history so far as I can state is as follows: About 60 years ago my Granfather(sic) kept the Victoria Hotel, Grimsby, and the cable was given to him. recently my Mother came across it amongst other curios my Granfather(sic) had collected and handed it to me thinking that I would be interested. The only information my Mother could give me about it was that it was a piece of a Submarine cable laid between Grimsby and Holland. Sorry I cannot furnish more definite information". (Sgd) E. Stanhope, Male Clerical Officer, Telephone Manager's Office, Liverpool. 14.6.39
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A0567
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SINGLE CORE POST OFFICE TELEGRAPHY CABLE, 1900's
Early armour protected cable for under ground use. Insulation may be Gutta Percha. Gutta percha was obtained from a variety of guttiferous trees throughout the Pacific Rim although different varieties produce materials of differing quality. The differences generally reflect the quantity of resin in the product with that from Pahang having the lowest resin content. Balata has one of the highest resin contents and was obtained from trees in the tropical regions of South America.
There is much confusion in the literature, and amongst collectors, as to “what gutta percha is”. In practical terms, and when addressing collectors’ items, the material is probably the whole residue from the latex, dried after collection from whichever tree was its source. This material tends to range from dark yellow through red to black. It is possible that it has undergone some degree of purification but, given the variations in initial composition, it would be extremely difficult to confirm this, even by detailed chemical analysis.
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A0572
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4 CORE ARMORED TELEGRAPHY CABLE, 1900's
Telegraphy cable heavily armoured and further protected with layers of hemp saturated in a water proof compound, for under sea use. It is possible of course that this could have been used for Telephony.
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A0576
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SINGLE CORE TELEGRAPHY CABLE, 1930's
Early Telephone or Telegraphy cable possibly for under sea use.
The insulation may be Gutta Percha. The Brass bands hold the sample together.
See Item A0572
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A0570
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4 POLE SWITCH WITH PEGS, 1920's
Early method of switching circuits using removable pegs.
Probably for bench testing in the Telegraphy or Electronics industry.
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A0805
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4 WAY SWITCH WITH CRANK, 1930's
School Laboratory Switch supplied by Griffin & George for Universities and Colleges.
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A0806
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