46 t h e ATLANTI C.
tlie ordinary construction. Tlie macliine, wliicli was
made by Messrs. Milne of Edinburgli, works up to
a pressure of 4 tons on the square incli.
On tlie port side opposite tlie laboratory tw’o cabins
have been fitted up as a liglit-room and a dark-room
for jiliotograpliic work, and a corporal of Royal Engineers,
0. Newbold, a very skilful pliotograplier, has
been established there. The management of a photo-
graiihic studio during a long sea-cruise is a matter of
great difficulty. All the circumstances—the motion,
the dampness of the air, and its vitiation hy vapours
of various kinds, and the extremes of climate which
affect the different reagents and materials, all tell
against the photographer ; yet, in spite of these disadvantages,
Newbold has already produced a large
number of very satisfactory pictures.
Hundreds of miles of line, of strength and material
suited to different purposes, are reeled and coiled in
everv available spot on the forepart of the main-deck
and elsewhere. When we left England we were provided
with 25,000 fathoms of bolt-rope for the
dredge, 10,000 fathoms 3-inch rope, 10,000 fathoms
21-inch, and 5,000 2-inch, and the supply has since
heen reneAved. The methods of sounding and dredging,
and the appliances used, are very much the same
as^tbose Avhich Ave employed in tbe ‘ Porcupine,’ and
Avbich I have described fully in a former A’olume.
Eor deep sounding Ave now very generally use a
1 The Depths of the Sea. An Account of the general Results of
the Dredging Cruise of H.M.SS. ‘ P o rcupine’ and ‘ L ig h tn in g ’ during
the summers of 18G8, 1869, and 1870, under th e scientific direction
of Dr. Carpenter, F .R S ., J . Gwyn Jeffreys, F.R.S., and Dr. Wyville
Thomson, F.R S. London : Macmillan and Co., 1873.
neat modification of the ‘ hydra ’ machine, devised
by Navigating-Lieut. C. W. Baillie. Tbe ‘B a illie ’
sounding instrument is represented in perspective in
/
F ig. 14.—The Baillie Souncling-Macliiue.
tbe position in w’hicb it is let go in Eig. 14 a , and in
section in tbe same position at b. Tbe tube a is
about 5ft. Gin. in length by 2^ inches in diameter.
:. ;i
u
Ij
s p i
f :
"4