Evening times-Republican. [volume] (Marshalltown, Iowa) 1890-1923, 1902-10-16
PROFILE
Government Will Make a Map
of the River Bed, Stumps
aud All
MEASURING DEVICE
New Invention Performing Valuable
Service in Locating snass in the Riv-
er-orisinally Designed to Measure
and Record River Depths-stump
Pulling Boat at Work.
,ecial to Times-Republican.


Special to Times-Republican.
Clinton Oct. 16.--A profile OF the bee
vi the Mississippi river IS the gigantic
task in which the United States snas
puller. Colonel Mackenzie is now en-
gagged. A new measuring device, q
wonderful mechanism, invented Dy
Captain Meigs, is being used in this
work.
Valuable as the device is as means
for ascertaining the derth OF the river
ut all points, 1t has proved Still more
valuable as snag locator. Whenever
the pole turns over a sunken tree or
log or other obstruction the change In
depth is instantly recorded on the drum.
The man in charge at once gives warn
ing and an investigator is made. IN
one instance the indicator showed an
even depth of water abou; eight feet.
All at once jump was made to three
feet and then the indicator again
dropped to eight. That meant that
there was something on the bottom.
The boat was tied UP and the Crap
5,ling hooks were passed over the shall
low spot. A large log was brought up,
which floated away. 70 make doubly
sure that all was right the, pole was
again passed over the SPOT. Once more
the graphing hooks were brought into
use and another section OF tree was
alished up. A third time the sharp varl-
alton in depth was noted. That time
the hooks brought up a large tree, roots,
branches and all. A fourth passage over
the spot showed an even depth, and u
was known that the channel was freed
nom three snags, wnere under the old
method all might have been missed or
only one removed.
The tackle carried al the Prov OF the
Mackenzie is capable OF lifting about
twenty tons. Often tee, II Its roots
and branches are attached, or If 1t is
sunk deeply in the mud or sand. Will
prove too much of load for the tackle.
In those cases explosives are used
!. Rack-a-rock" is the explosive used
compound which is claimed to be 80 per
cent as powerful as dynamite and muln
less dangerous TO handle. Its ingredi-
ents are kept separate until 1t Is re-
uuired for use, and then the mate mixes
il UP and prepares the charge EXPERT
ence has taught him the proper amount
for the work required and short work
is made Of any obstruction which
proves too obstinate for the block and
tackle or the powerful steam capstan.
So many charts and profiles OF the
mississippi have been taken that the
engineers know the bottom OF the river
almost as we'll as the engineer of the
railroad knows the ups and downs OF
it's grades. New charts are prepared
almost every year, ane the charts and
project sheets are corrected and ammo
tated so carefully and profusely that
only a man accustomed to working on
hem is able to tell anything about
ITEM. One profile OF the river bottom
was made in 1864. ana subsequent pro-
files have been traced over the original
anti the list of colored inks and COM
;,inations of dotted and dashed lines IS
almost exhausted in the endeavor 10
make each tracing plain.