attended by the Princess Alexandra and Advice, proceeded to sea, veering
out the shore end of the Cable in the channel marked by Lieutenant
White, and at 10·30 p.m. buoyed the end 26 miles W.N.W. of Valentia, in
75 fathoms of water. A message was sent through the Cable to
Foilhummerum, and a dispatch was forwarded to the Great Eastern, in
Bantry Bay, to come round with all speed. This order was obeyed with
such diligence that her appearance off the harbour of Valentia was
reported in Knightstown soon after 7 o’clock next morning, July 23.
H.M.S. Terrible and H.M.S. Sphinx were in company. The Hawk, which
returned from the Caroline in the course of the night, got up steam and
left Valentia Harbour about 10 o’clock a.m., July 23, with a party of
visitors and passengers for the Great Eastern, among the former being
Sir R. Peel, the Knight of Kerry, and Captain Lord John Hay. By 3 p.m.
the Hawk had reached the flotilla, which lay around the buoy, preparing
for the great enterprise. She was just in time; the end of the shore
Cable was about to be spliced and joined with the landward end of the
main Cable from the after tank of the Great Eastern, and the boats of
the Great Ship and of the two men-of-war, were engaged in carrying the
end of the main Cable to the Caroline. Sir R. Peel, the Knight of Kerry,
Lord John Hay, Mr. Canning, and others, got on board the Great Eastern
in successive trips of the Hawk’s boats; but the ladies, who had come so
far and had suffered too in order to see the famous vessel, could not
venture, as there was a swell on which made it difficult to embark or
approach the gangway ladders. After an hour’s enjoyment of the almost
terrestrial steadiness of the Great Eastern, the visitors departed, amid
loud cheers, to the Hawk, and at 5·10 p.m. it was reported by the
electricians that the tests of the splice between the main Cable and the
shore end were complete, and that the shore end was much improved in
its electrical condition by its immersion in the water. The boats were
hoisted in by the men-of-war and by the Great Eastern, adieux and good
wishes were exchanged, and, with hearts full of confidence, all on board
set about the work before them.
The bight of the Cable was slipped from the Caroline, at 7·15 p.m., and
the Great Eastern stood slowly on her course N.W.¼W. Then the Terrible
and Sphinx, which had ranged up alongside, and sent their crews into the
shrouds and up to the tops to give her a parting cheer, delivered their
friendly broadsides with vigour, and received a similar greeting. Their
colours were hauled down, and as the sun set a broad stream of golden
light was thrown across the smooth billows towards their bows as if to
indicate and illumine the path marked out by the hand of Heaven. The
brake was eased, and as the Great Eastern moved ahead the machinery of
the paying-out apparatus began to work, drums rolled, wheels whirled,
and out spun the black line of the Cable, and dropped in a graceful
curve into the sea over the stern wheel. The Cable came up with ease
from the after tank, and was payed-out with the utmost regularity from
the apparatus. The system of signals to and from the ship was at once in
play between the electricians on board and those at Foilhummerum. On
board there were two representative bodies--the electricians of the
Telegraph Construction and Maintenance Company, under M. de Sauty, and
the electricians of the Atlantic Telegraph Company, Mr. Varley,
Professor Thomson, and assistants. The former were to test the
electrical state of the Cable as it was being payed-out, and to keep up
signals between the ship and the shore. The latter, who had no power of
interference or control, were simply to report on the testing, and to
certify, on their arrival in Newfoundland, whether the Cable fulfilled
the conditions specified in the contract. The mechanical arrangements
for paying-out the cable were in charge of Mr. Canning,
engineer-in-chief to the Telegraph Construction and Maintenance Company,
who might be considered as having supreme control over the ship _ad
hoc._ In the space on deck between the captain’s state-room and the
entrance to the grand saloon, was the Testing-Room--a darkened chamber,
into which were led conducting wires from the ends of the Cable, for the
ordeal to which they were subjected by the electricians, at a table
whereon were placed galvanometers and insulation and resistance-testing
machines.
The instructions for signalling, determined upon by the
electricians of the Telegraphic Construction and Maintenance
Company, were as follows:--
1. During the paying-out of the Cable, from the moment of starting
until the end is landed at Newfoundland, electrical tests will be
applied without intermission.
2. The tests will be for insulation, for continuity, and to
determine the resistance of the conductor, the whole length of
Cable being joined up in one length.
3. Each series of tests will commence at the hour (Greenwich time),
and will last one hour.
4. The insulation test will consist of 30 minutes’ electrification
of the Cable, commencing at the hour, and lasting till 30 minutes
past the hour. Readings of the galvanometer to be taken every
minute, commencing one minute after contact with the battery, the
battery to consist of 40 cells.
5. At 30 minutes past the hour signals will be received from the
shore for 10 minutes. Unless the ship wishes to communicate with
shore by special speaking instruments, in which case, instead of
receiving signals from the shore, ship will put on a C to E current
to oppose deflection on shore. Galvanometer to arrest shore
attention, and when joined, give the call as in paragraph 9: the
ordinary signals will be 5 reversals of 2 minutes each.
6. At 40 minutes, C of Cable will be taken to 10 minutes.
7. At 50 minutes signals will be sent to the shore, and for the
ordinary signals 5 reversals, 2 minutes each, commencing C to E.
8. Then a repetition of the same tests to be made and continued
without any interval.
9. In case it becomes necessary to speak to shore by speaking
instruments, the signal will be given at the 50 minutes, and at the
30 minutes, as in paragraph 5, by sending 8¼ minutes’ reversals,
commencing Z to E, and changing over to the speaking instruments,
on receiving acknowledgment of call from shore (which will be also
8¼ minutes’ reversals), communication or message to be sent, and
when acknowledgment of message and reply (if any) is received, then
the system of testing is to be resumed, as if no interruption had
taken place.
10. Every 50 nauts. of Cable payed-out will be signalled at the
same time (viz., at the 50 mins.), thus, instead of 5 reversals of
2 minutes, 10 reversals of 1 minute will be made commencing Z to E.
11. Every 50 nauts. distance run will be signalled to the shore;
the signal will be 2 reversals (commencing Z to E), each 2 minutes’
duration--2 reversals, each 1 minute’s duration, and 2 reversals,
each 2 minutes’ duration.
12. Should any defect in signals be perceived, or bad time kept,
notice will be given to the shore by signalling at the 50
minutes--thus, by giving 2 reversals of 5 minutes’ duration,
commencing Z to E.
13. In sounding, signal will be one current of 10 minutes’
duration, Z to E.
14. Land-in-sight signal will be likewise one current of 10
minutes’ duration, Z to E.
15. Greenwich time will be kept, but a column will be devoted in
journals and sheets to ship’s time.
16. After the insulation test is taken, it is to be worked out
thus--The same deflection at the 15th minute’s reading will be
obtained with the same battery through resistance, and a shunt to
the galvanometer. The amount of resistance multiplied by
multiplying power of the shunt, and galvanometer multiplied by the
length of the Cable, will give the G. p. R. pr. nt.
17. The copper resistance of the Cable will be taken after 5
minutes’ electrification.
18. No change in the instruments, wires, or connections (other than
the batteries, if necessary), to be made on any account, unless
such instruments, &c., become defective--any necessary change to be
made as quickly as possible.
19. Should the rolling of the ship generate a magnetic current of
sufficient strength to embarrass the signals, a stronger current
for the signals will be put on on shore, and a shunt used with the
galvanometer on board, notice to the shore to put on more power
will be given by one current of 5 minutes, commencing Z to E, and 5
reversals of 1 minute’s duration.
20. The iron earth of the Cable will be used both on board and on
shore--other earths, however, to be in readiness for use, if
necessary.
21. Full particulars of every test and every occurrence in the
testing-room to be entered in journal, together with the name of
the electricians on duty, and the time of their coming on and going
off duty.
22. After the end is landed, should signals fail, the paying-out
system to be resumed until signals are re-established.
23. In case of a minute fault appearing, such as will partially
affect the signalling, but which will not stop the communication
entirely, notice will be given to shore to reduce battery power.
Such notice will be given at the 50 minutes, by sending 5 reversals
of 1 minute each, commencing Z to E, and 1 current of 5 minutes’
duration.
24. A proper supply of lamps, glasses, oil, and wicks; instrument
ink and instrument paper, in sufficient quantities; paraffin,
wicks, and spare lamp-glasses for the instrument lamps;
lamp-brushes, tools, sulphate of copper, stationery, &c., to be
always ready for use.
25. No person except those on duty, and the engineers and the
officers authorised by the Atlantic Telegraph Company, to be
allowed in the instrument room on any pretence.
26. The batteries to be kept in an efficient state, especially
those for sending reversals--their force taken periodically, and if
any variety occur, they must be renewed, or brought up to the
original force.
27. Supplies of every material needful for such purpose to be in
constant readiness.
28. The actual end of the Cable to be brought to the instrument
tables, and well insulated.
SHIP’S SIGNALS.
29. Ordinary.--5 reversals, commencing C to E, each 2 minutes.
To open communication.--8 reversals, commencing Z to E, each ¼
minute.
50 nauts. payed out.--10 reversals, commencing Z to E, each 1
minute.
50 nauts. distance run, signal will be, 2 reversals, each 2 minutes, commencing Z to E.
“ “ “ 2 “ “ 1 “ “ “
“ “ “ 2 “ “ 2 “ “ “
Defective signals.--2 reversals, commencing Z to E, each 5 minutes.
In soundings.--1 current of 10 minutes, Z to E.
Land in sight.--1 “ “ “ “
Notice to increase power.--1 current of 5 minutes, commencing Z to
E, and 5 reversals of 1 minute’s duration.
Notice to reduce power.--5 reversals of 1 minute, commencing Z to
E, and 1 current of 5 minutes.
SHORE.
1. During the paying-out of the Cable, from the moment of starting
until the end is landed at Newfoundland, a system of testing will
be applied without intermission.
2. The tests will be for insulation, for continuity, and to
determine the copper resistance of the conductor.
3. Each series of tests will commence at the hour (Greenwich time),
and will last 1 hour. Both the insulation and C R tests will be
made on board.
4. The insulation test will be made on board, and to enable that to
be done, the end of the Cable must be insulated on shore for 30
minutes, commencing at the hour.
5. At the 30 minutes past the hour, signals will be sent to the
ship for 10 minutes. Should ship at this time desire to open
communication, ship will put on a current so as to oppose shore’s
current on his galvanometer, to arrest shore’s attention, and will,
when gained, give the call as in paragraph 10.
6. The ordinary signal will be 5 reversals of 2 minutes’ duration,
commencing C to E.
7. At the 40 minutes, Cable to be put to earth direct, without any
instrument being in circuit.
8. At the 50 minutes, signals will be received from the ship. The
ordinary signal will be 5 reversals, each 2 minutes’ duration.
9. Then a repetition of the same series to be made and continued.
10. Should ship desire to open communication by special speaking
instruments, notice will be received by a signal of 8 reversals
(giving a deflection the opposite to the ordinary signals) of ¼
minute’s duration.
11. After returning the same signal to the ship as an
acknowledgment, the speaking instruments to be put in circuit, and
the message from the ship received, and when acknowledgment of
message, or reply, is given, the regular system of signals to be
resumed as if no interruption had occurred.
12. Every 50 nauts. of the Cable payed-out will be signalled to the
shore by signal (instead of the ordinary signals). This signal will
be 10 reversals of 1 minute each--the first current giving a
deflection the opposite side to the first current of the ordinary
signals.
13. Every 50 nauts. distance run will be signalled to the shore:
the signal will be 2 reversals of 2 minutes’ duration, 2 reversals
of 1 minute’s duration, and 2 reversals of 2 minutes’ duration--the
first current giving a deflection opposite to the first deflection
of the first current of the ordinary signal.
14. Should ship receive weak or defective signals, or bad time
kept, notice will be given by sending 2 reversals of 5 minutes
each, commencing the opposite side to the ordinary signals.
15. When the ship gets into soundings, notice will be given by
sending one current of 10 minutes’ duration, the opposite side to
the first current of the ordinary signals.
16. When land is in sight, notice will be given by the same signal.
17. Greenwich time to be kept, but a column to be devoted to local
time in the journals and sheets.
18. No change in instruments, wires, or connections (other than the
batteries, if necessary), to be made on any account, unless such
instruments become defective, and any necessary change to be made
as quickly as possible.
19. Should the rolling of the ship generate a magnetic current of
sufficient strength to embarrass the signals, a stronger current
for the signals must be put on by shore on receiving notice from
the ship; the notice will be given by 1 current of 5 minutes’, and
5 reversals of 1 minute’s duration.
20. The iron earth of the Cable to be used both on board and on
shore: copper earths, however, will be in readiness for use if
necessary.
21. Full particulars of every occurrence in the testing-room will
be entered in journals, together with the names of the electricians
on duty, and the time of their coming on and going off duty.
22. When the end is landed at Newfoundland, should signals fail at
any time, the paying-out system to be resumed until signals pass
again freely.
23. On receiving a signal of 5 reversals of 1 minute’s, and a
current of 5 minutes’ duration, shore must reduce the battery power
used for sending reversals by one-half, and on a repetition of the
same signal again reduce the power one-half, until (should notice
continue to be given to that effect) the minimum of power be
reached.
24. Shore must not have the privilege of opening a conversation, or
to use or call for the use of the special speaking instruments,
under any circumstances, except to give notice of any accident that
may cause an interruption of signals, or that may affect the safety
of the Cable or signals.
25. Should any interruption of signals from the ship occur by
reason of an accident on board, shore will continue to free the
Cable at the usual time, and to put to earth direct at the usual
time, and in the intervals to put into circuit with the Cable a
galvanometer, and watch the same for signals, and continue doing so
until communication with the ship is restored, or information is
received by other means from the ship.
26. On re-establishment of communication, shore must not ask any
questions, but take the resumption of signals as an indication of
all being well again, and will continue to follow the series of
tests as if nothing had happened.
27. Shore will take time from the ship; should any irregularity in
the reception of signals from the ship occur, such irregularity
must be entered in journals, and must not form a ground for shore’s
altering his time, but shore must follow blindly every change
(should one take place), as if the most correct time had been kept.
28. A proper supply of lamps, glasses, oil, and wicks; instrument
ink and instrument paper, in sufficient quantities; paraffin,
wicks, and spare lamp-glasses for the instrument lamps;
lamp-brushes, tools, sulphate of copper, stationery, &c., to be
always ready for use.
29. No person, except those on duty, and the officers authorised by
the Atlantic Telegraph Company, to be allowed in the instrument
room on any pretence.
30. The batteries to be kept in an efficient state, especially
those for sending reversals--their force taken periodically, and if
any variation occur, they must be renewed, or brought up to the
original force.
31. Supplies of all materials necessary for such purpose to be in
constant readiness.
32. The actual end of the Cable to be brought to the instrument
tables, and well insulated.
SHORE SIGNALS.
33. Ordinary.--5 reversals, each two minutes, commencing C to E.
34. To open communication on acknowledgment.--8 reversals, each ¼
minute, commencing Z to E.
As the voyage of the Great Eastern promised to be so interesting to
electricians and engineers, several young gentlemen who worked in the
testing-room and in the engineer’s department received a passage, as we
have mentioned, but there was no person on board who was not in some way
or other engaged on the business of both companies, or connected with
the management of the ship. The voyage commenced most favourably. The
rate of speed was increased to 3 knots, then to 4 knots, then to 5
knots, and finally, to 6½ knots an hour, and the Cable flew from each
coiled flake as if it were eager to push up through the controlling
bands of the so-called crinoline, and to plunge into the sea. At
10·p.m., Greenwich time, 50 miles of Cable had been payed-out, and the
process continued to midnight with equal ease and regularity. In order
to make each day’s proceedings distinct, and to take the reader over the
course so that he can follow the expedition readily by the aid of the
accompanying chart, I propose recording events in the form of a diary.
[Illustration: ATLANTIC TELEGRAPH CABLE 1865.
Chart
Shewing the Track of
THE STEAM SHIP “GREAT EASTERN” ON HER VOYAGE FROM VALENTIA TO
NEWFOUNDLAND
WITH THE SOUNDINGS, THE DAILY LATITUDE AND LONGITUDE, THE DISTANCE RUN
AND THE NUMBER OF MILES OF CABLE PAID OUT
???? DAY & SON (LIMITED)]
[Illustration: From a drawing by R. Dudley London. D.T & Sou. Limited.
Lilh.
SPLICING THE CABLE (AFTER THE FIRST ACCIDENT) ON BOARD THE GREAT EASTERN
JULY 25TH.]
_Monday, July 24th._--The morning was exceedingly fine, and the ship
proceeded steadily at an average rate of 6 knots an hour, with a light
favouring wind and a calm sea. Those who were up betimes had just taken
a turn or two on deck, watching for the early dawn, when they observed
some commotion in the neighbourhood of the Testing-Room, and soon
afterwards the ship’s engines were slowed and stopped. According to
Professor Thomson’s galvanometer, which is used in the system employed
in testing, a ray of light reflected from a tiny mirror suspended to a
magnet travels along a scale, and indicates the resistance to the
passage of the current along the Cable by the deflection of the magnet,
which is marked by the course of this speck of light. If the light of
the mirror travels beyond the index, or out of bounds, an escape of the
current is taking place in the Cable, and what is technically called
a fault has occurred. At 3·15 a.m., when 84 miles of Cable had been paid
out, the electrician on duty saw the light suddenly glide to the end of
the scale, and then vanish. The whole staff were at once aroused--the
news soon flew through the ship. After testing the Cable for some time
by signalling to and from the shore, Mr. de Sauty satisfied himself that
the fault which had occurred was of a serious character, and measures
were taken accordingly to rig up the picking-up apparatus at the bow, to
take in the Cable till the defective portion was reached and cut out.
Such an early interruption to our progress caused a little chagrin, but
the veterans of submarine telegraphy thought nothing of it. Whilst the
electricians were testing, to obtain data respecting the locality of the
fault, the fires were got up in the boilers of two small engines on deck
to work the picking-up machinery. At 4 a.m. a gun was fired by the Great
Eastern to call the attention of the Terrible and Sphinx to our
proceedings, and they were also informed by signal of the injury.
Notwithstanding the skill and experience of the scientific gentlemen on
board, there was a great vagueness of opinion among them respecting the
place where the fault lay. Some believed the defective part was near the
shore, and probably at the splice of the shore end with the main Cable;
others thought it was eastward or westward of the same place; and
calculations, varied by uncertain indications given by the currents
showing that the fault itself was of a variable character, and permitted
the currents of electricity to escape irregularly, were made by the
scientific staff, which fixed it at points from 22 to 42 miles--one at
60 miles--from the ship. But repeated observations gave closer results.
Mr. Varley came to the conclusion that the fault was not very far from
the ship; and Mr. Sanders, a gentleman who had much experience in
fault-finding, arrived at the conviction that it was not more than 9 or
10 miles astern.
The best test taken by Mr. Saunders, 1·30 a.m., Greenwich time, July 25,
after the Cable had been cut down to 78·5 miles, gave--
Resistance, shore end disconnected, 2,600 units.
“ “ to earth, 312 “
Let _a_ and _b_ be the lengths of Cable-conductor, having resistances
equal to the first and second of these numbers; _l_ the length of Cable,
and D the distance of the fault. The ordinary formula gives
_____________________________________
D=_b_--√(_a_-_b_)(_l_-_b_)
Hence, _l_ being 78·5, and _a_ and _b_ being calculated from the
observed copper-resistance of the conductor in the after-tank, and
various assumed temperatures of the sea, we should have, were the
measurements perfect, results as follows:--
+---------------------------------------+----------------------------------+
|Copper resistance of Cable | Distances of the fault calculated|
|in after tank, per nautical mile, | accordingly from end in ship, |
|observed 4.44 units at 61° temperature.| when cut at 78.5 miles of |
| | cable from shore end. |
+---------------------------------------+----------------------------------+
|Hence 4·42 units at 59° temperature | 6·7 miles. |
| 4·37 “ 53° “ | 10·1 “ |
| 4·25 “ 40° “ | 22·0 “ |
| 4·02 “ 35° “ | 27·2 “ |
+---------------------------------------+----------------------------------+
This would give 22 miles for the most probable distance of the fault, as
40° is the most probable mean temperature of the first submerged length
of 75 miles. The true distance proved to be very nearly 3 miles. The
discrepance is owing partly of course to want of absolute accuracy in
the measurements, but probably more to the variation of the resistance
of the fault during the interval between the two measurements.
Iron chains were lashed firmly to the Cable at the stern, and secured to
the wire rope carried round outside the ship to the picking-up apparatus
at the bows. As the paying-out stopped, a strain came on the Cable,
which was down in 400 fathoms of water, and it needed nice management to
keep the ship steady, as she had no steerage way. The Cable, having been
shackled and secured, was severed at 8·50 a.m., and flew with its
shackling into the sea, plump astern. The stoppers which held the wire
rope were released, and the rope was payed-out rapidly as the Cable
sunk, in order that the ship’s head might be brought round, if possible,
so as to take the Cable in over the bows in a straight line with its
course.