The Hawaiian gazette., 1875-08-04
The Voyage of the ChaIIenger.

The Voyage of the Challenges.
H. B. Ms ship Challenger, engaged on a
scientific voyage around the world, arrived at
this port on Tuesday, July 81, from Yokohama,
japan. Leaving Portsmouth, England, on the
2lst of December, 1872, this vessel, first under
the command of Captain Mares and now under
that of Captain Thomson, has been engaged in
the great work of sounding the ocean depths,
and exploring its mysteries She has been a
wonderful traveller since leaving England
thirty-one months ago, having in that time
visited some fOrty-two ports in Europe, Africa.
Australia, the East Indies, China and Japan,
and sailed 1854 miles. The amount of scien-
tifc observation and investigation accom-
plished by her officers and scientific staff Cat
the head of the latter is Professor G. Wyville
Thomson) must be something prodigious.
The instruments for sounding, dredging, and
for ascertaining the temperature, are all of the
latest invention, and are curiously suggestive.
We are indebted to a gentlemen on board the
Challenger for description of some of these,
promising that sounding wire is used six
miles in length.
The dccunuLatOr of about 40 or so
india rubber bands, q inch in diameter, and
three feet in length. They are capable of
stretching seventeen feet, when they each ex-
ert pressure of seventy pounds At the bot
tom of the accumulators are two discs of wood,
through holes in which each of the bands pass
and are attached to a block, through which
the dredging line passes.
The sounding rod-is an improvement on
the first supplied on leaving England by Lieu
tenant Bailey, r. N 1t is cylinder of iron
tubing, three inches in diameter, and about
four feet long, having at its bottom butterfly
valve. On the upper part is a mechanical con-
trivance for letting go the weight on the rod
touching the bottom. The weights are ll2
pounds each of cylindrical form, with hole
through the centre. Through this hole the
rod is passed, and as many weights put on as
found necessary, one for every 900 fathoms
At the bottom of the last weight small iron
ring is reved on the rod, to which is attached
a piece of iron wire, about ten feet long. The
blight of this wire is passed over "ketch,"
and the rod being lifted the weights rest on the
iron ring. By their reaching and resting on
the bottom, the wire is forced off the ketch,
and the rod being hauled up by the line clears
itself from the weights, which remain at the
bottom.
The slip 'oater bottle, for bringing up water
from the bottom, consists of brass rod, with
three radiating plates to strengthen it and to
act as guide for brass cylinder which en-
closes the water. AT the bottom and half way
down the radiating plates, are two finely
ground sections of cones, and the brass cylin-
der is SO arranged that its upper and lower
surfaces fit with great accuracy on these cones,
thus enclosing anything that may happen to
be between them. At the top of the rod is a
brass tumbler with a slit in it; to the tumbler
is attached lanyard to fasten the bottle to the
headline, and over the slit is placed the blight
of line the-ends ot<Hwhich are secured to the
cylinder, by means of which the cylinder is
kept suspended above the cones while the bot
tie is descending, thus allowing the water to
pass freely through it. Directly the strain on
the lead-line above is released through the
bottle reaching the bottom, the tumbler falls
over, pushing off the line that suspends the
cylinder, leaving it free to fall on the two
cones. 1t thus efectually encloses specimen
of the bottom water. A tap is arranged at the
bottom, SO as to draw off the water for analy-
sis, &c.
The Miller C1Ss1d Thermometer The ther-
mometers used to ascertain the temperature of
the bottom, or at any intermediate depths, are
self-adjusting maximum and minimum thermo-
meters, constructed to resist the pressure of
the water. They are the invention of the late
Mr. Miller, F. R. S., and are made and tested
hence they are called Miller-Casella thermo-
meters. Each consists of curved tube with
a bulb at each end; the left bulb is filed with
creosote, the expansion and contraction Of
which gives the temperature. The creosote
acts on a small quantity of mercury in the o
part of the tube, which moves up or down as
the creosote expands or contracts. The other
tube is partly filled with creosote, and in addi-
ton has small quantity of air in it, at the
pressure of the atmosphere to act as buffer
on the mercury in the tube, to keep it always
in contact with the creosote in the bulb. In
each part of the tube above the mercury is an
index shaped like dumb-bell, being of steel,
and the other index is retained in its place
when the mercury recedes from it by hair
attachment, which pressing against the glass
tube of the thermometer, acts as a spring.
These induces are set with magnet.
It is evident that the bulb of the thermome-