The Black Hills union. [volume] (Rapid City, Pennington County, Dakota [S.D.]) 1889-1904, 1904-01-29
some instances. and thus reduce the too
liberal supply of hat character of J
goods, 4
NEW SOUNDING DEVICE.
Machine for Testing the Uncharteo

Seas.
Wednesday afternoon there was made in
the channel just below the arsenal point
a practical test of a new device which
may be termed a continuous profile
sounding machine and which has been
designed not only for the purpose of all
ordinary soundtngs, but with special ref
erence to the protection of the hulls of
great battleships, several of which have
in recent years been very seriously dam
aged by striking upon rocks or other OBJ
structions, uncharted and utterly unknown
to Mariners.
1t goes without saying thai any system
of sounding which will reduce to the min
imum the chance of failure to locate in
dividual rocks or other comparatively
small distractions or elevations above
the normal level or slope of the bottoms
of harbors or coast waters Is greatly to
be desired. especially because Of the ex-
cessive danger from such n source to the
battleships, which generally are of great
draught, and however slight a blow upon
whose hulls is sure to cause immensely
expensive repairs, not to speak of the dan
ger to life. There Is at present no other
means in use to obtain ordinary sound
tngs than the method of "heaving the
lead" This time-honored method is nee
essarily crude and incomplete in results.
At the exact points where the lead Is
"heaved" the depth of water is doubtless
very accurately determined, or would be
II the vessel from whose deck the lead
Is thrown could be at that moment sta
tionary. But ~soundings must be taken
ordinarily from a vessel under a fair rate
of speed-about three or four knots, for
jnstance-and under such conditions the
lead-line, unless manage by a quite ex-
pert man, has SO great an inclination from
a perpendicular to the water surface, both
before and after passing directly over the
lead, that a considerable factor Of error
Is unavoidable. Again, In running a line
Of soundings with the lead, no matter
what sudden rise of the bottom, rock.
srnken wreck or other obstruction may in
fact exist between any two points actual
ly tested, the ordinary method gives no
indication of them, and the only means
of locating such distractions or abnor-
NAL elevations of the bottom is by cross
sectioning the work as closely as posi-
bic, so as to confine such distractions
within spaces Of the minimum size.
Tho device tested Wednesday consists
of a graduated rod OF some thirty feet in
length, adjusted to the side of a boat,
launch or amy sort Of vessel, running free
ly up and down, approximately perpendic-
ular to the water surface, and terminal
ing at the bottom III a wheel Of sufficient
weight in itself 10 insure contact with
the bottom at any speed otherwise practic-
able for sounding. BY suitable ADJUST
ments the rod is compelled to roll along
on the bottom while maintaining its YER
teal position, and thus is extremely SEN
sitive to any change whatever in the pro-
file OF the bottom along the line upon
which the vessel is running.
During the test an obstruction was
struck in the course of u uniform grade,
and instantly shown by a sudden rise of
the rod and as sudden a fall a moment
later. The obstruction could hardly nave
been larger than a barrel. The recorder,
of course, noted the readings of the rod
at the very moment of striking, securing
the summit elevation and the depth OF
water Immediately after resuming the
normal grade. The wheel Is SO arranged
as to carry the rod easily over any OBJ
struction. On this occasion several lines
were run. their locations being determined
by the use of two seXtants, the observers
noting positions Of signal stations previ-
ously established, as usual, and the re-
suits can be plotted up in profile form
with very great accuracy. The readings
of the rod were taken at close. regular
intervals and at all salient intermediate
points.
This device Is the invention Of a young
Marylander now resident in Washington,
and all Of the practical tests SO far made
nave been wholly under his control and
direction.