Crystal Palace International Electric Exhibition 1881-82
År: 1882
Sider: 102
UDK: 621.30 : 06 (064)
DOI: 10.48563/dtu-0000189
Official Catalogue, Edited by W. Grist with Specially Prepared Plans, showing the position of each exhibitor and indicating the spaces lighted by the various sytems.
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CATALOGUE.
HER MAJESTY’S GOVERNMENT.
postal IBqm'tment.
The Exhibits of Her Majesty’s Government are numbered, independently
of the rest of the Catalogue ; each. Catalogue number corresponding to
that of the Exhibit.
MODERN APPARATUS AS USED BY THE BRITISH
POST OFFICE.
[1.] DOUBLE-CURRENT SOUNDER SET.
This apparatus is used for transmitting messages which, are
read by sound. The dots and dashes of the Morse-Alphabet are
given by the falling and rising of the brass lever to which
the armature of the electro-magnet is fixed. The key in this
instrument sends a current in. one direction when depressed, and
a current in the reverse direction, when raised. These currents
actuate a polarised relay, which, works the local sounder.
[2.] WHEATSTONE'S AUTOMATIC SET.
The messages are read by the dots and dashes being printed
in ink upon a strip or ribbon of paper. It is used chiefly for
(e press” work, and will transmit at the rate of 200 words a
minute and upwards. The message is punched out on a slip of
paper in the first instance.
[3.J FAST REPEATER BOARD.
Used in connection, with, the Wheatstone automatic apparatus
for “repeating” over long lines. The repeater set is placed at
a point intermediate between the transmitting and receiving’
stations, and increases the speed of working.
[4.] FAST DUPLEX REPEATER.
_ apparatus is used for repeating th.e signals when, working
Wheatstone’s automatic on the duplex system, and may be also
used for ordinary single working.
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