, 1865-06-23

4OpR SO4IS Out5 VA ~ SO1S'bIbiJ hbHI'ShS
that a sudden rise of the ships stern from
a wave gives the cable a strain that re-
quires instant removal of the brakes to
relieve it. This is accomplished by Il
dynamime!er placed on the cable after it
leaves the paylng-opt machine and be-
fore it passes over the wheel astern into
the Atlantic. This dynamimeter is only
a heavy wheel resting on the rope, but
fixed in an upright frame, which allows
it to slide freely up and down, and on
this frame are marked the figures which
show exactly the strain in pounds on the
cable. Thus, when the strain is low the
cable ~slackens, and the dynamimetcr
sinks low with it; when, on the contra
~, the strain is great, the cable is drawn
''taut,'' and on it the dynamimeter rises
II. its fall height. When it sinks too low,
the cable is generally running away too
fast, and the brakes nave to be applied to
cheek it, when, on the contrary, it rises
rapidly The tension is dangerous, and Tie
brakes have to be almost opened TO re-
lieve it. The sim p.icity Of the apparatus
for opening and shutting the brakes is the
most beautiful of all. Opposite the dy-
namimeter is placed a tlIler-Wheel, and
the man ia charge of this never lets its it
90 nor slackenS in his attention for an
instant, but watches the rise and fall Of
the dynamimeter as a sailor at the wheel
watches his compass. 4 single move
ment Of this wheel to the right puts
the brakes on, a turn to the left opens
them. A good and experienced brakes
man will generally coUtriyc to avoid eli
Their cxtcme of a high or low strain,
though there are few duties connected
with the laying of submarine cables
which are more anxious and more res
ponsible while they last than those con
nectcd with The management ofthe brakes.
The whole machine yesterday worked
beautifully, and with so little friction
that when the brakes were removed a
weight Of 200ib wa sufficient TO draw
the cable through il.
In order to guard against any possible
sources Of accident, every prccaution has
been made in case of The worst, and, in
the event of very bad weather, for cutting
the cable adrift and bouying it. For this
purpose a wire rope of great strength and
no less than five miles long, having a dis
|tinctive mark at every 100 fathOms, will
be taken in the Great Eastern. This, of
course, is only carried in case Of despe-
rate eventualilies arising, and in the earn
est hope that not an inch Of it will ever
be required. II, unfortunately, its servi-
Ces should be wanted, the cable would be
firmly made fast to its extremity and so
many hundred fathoms of the wire rope
according to the depth of water the cable
was in measured out. To the other end
of the rope an immense buoy would he
attached, and the whole then cut adrift
and left TO itself till better weather. In
the experimental cruises which were IN
dertaken before the starting Of the last
Atlantic expedition this attempt at bouy-
ing the cable was often tried in the deep
water Of the Bay Of Biscay, but never
with any great success, and in very deep
water it would be a most f%orlorn hope in
deed TO try it at all.
After going all over the works yes.er-
day, and inspecting all the apparatus, the
Visitors left the buildings shortly before
6 o'clock, and were entertained by the di-
rectors of the Telegraph Company at q
banquet at the Ship at Greenwich, when
"Success TO the Atlantic Telegraph" was