Evening star. [volume] (Washington, D.C.) 1854-1972, 1899-09-09
DEPTHS OF GREAT LAKES
The photographic Office at Chicago Takes
New Soundings.
No System of Lakes Presents as Wide
Variations of Extreme Depth
as This One.
From the Chicsgo Chronicle.

| If the chain OF great lakes which bound
the northern limits of a portion of the
| United States could be reached to the level
| of the sea two of the chains would be prac
! ticaly wiped off the face of the earth.
| Lake Michigan would become two lakes
| much smaller than the present majestic
| body of water which lies OFF Chicago.
| Chicagoans could travel on what is now
| the bottom Of the lake far north a
| point midway between the shores off Mil
| waukee and Grand Haven without getting
| their feet wet. But while this statement
| duly explained shows the great depth of
| the great lakes. the mariner is concerned
| only with the shore line and any obstruc-
| tons of navigation in the usual channels.
The recent grounding of a huge freghter
| off Drummond Island in the northern
| straits shows how faulty the surveys and
| soundings of the chain are relative to mod
| ern vessels.
| The freighter standing up the channel to
| the 800" was in what her chart declared
| to be thfrty-four feet of water. AS she
draws about thirteen she had plain sailing.
| But when all were snug and confident the
| ship drove onto rock and was stuck fast
| aground. This rock lies but ten feet below
| the surface. Ten years ago it was no OBJ
| struction for the reason that the average
| draught of lake vessels was about eight
| feet on the load water line. Today it is
| much nearer fifteen even eighteen.
| the soundings of a year ago are not alto
| gether reliable in channels dotted with
| small islands. By the time the pilots chart
| for the month Of September Is prepared ac-
curate soundings all about this rock will
he made. rendering 1T no longer a menace
| to shipping.
But with all that money ard skill can do
| the fact remains that no body of water
| no bay which will float vessel of any
| size, Is known to the men who go down to
| the sea In ships. The government, through
the engineers Of the army. makes frequent
| soundings In harbors and along shore lines
Changes in types of vessels. changes In
currents. changes in water levels when
| found to be permanent all require modif-
| cations of existing charts. Probably no
| system Of internal waterways is so thor
oughly charted as the great lakes. Yet 1t
| is no infrequent thing for some vessel to
run aground on concealed Instructions
| where the detailed sounding charts estab-
| fish a depth of water more than three
times sufficient to float the vessel
| When that freighter went aground the
| first duty Of the captain, of course, was
| to provide for the safety Of the vessel and
| crew. His examination revealed no serious
damage to his ship no boats were sent off
| to the nearest port Drummond, and tugs
| and lighters sent for to haul her off the
rock. Seeing his ship was resting easy the
] captain took his bearings. He set his
quadrant and established the exact loca-
| ton of the rock. He took the line along
| the east shores of two small islands for
ward and to starboard. Then he took the
| line which ran from the Drummond light
| land to the north of port. The intersec-
ton Of these two lines is the location of
the sunken rock
The directions Of the compass these two
| lines followed, with the distance from the
| shore of Drummond Island due south, with
| the latitude and longitude of the island
| and ship make 1t matter of mathematical
| exactness. Any skipper holding a license
| as shiomaster on the lakes can take the
report made by that captain and run d.
rectly onto the rock as easily as he can sail
| chicago ri
Will be grated into official records and new
sound1ngs be made at once The obstruc-
non IS wholly within American waters, as
the Canadian boundary runs east and north
of the point. In a short time engineers vii!
go out there and make soundings all around
that point to determine the nature and ex-
tent of the obstruction. 1t will likely mar
row the channel quite bit for heavy yes
sells.
Six years ago the old Michigan made
series of harbor soundings for Chicago. No
| lake port in the whole system has been
more thoroughly explored than this. Yet
W. j. Wilson of the hydrographic office
| says that it would not be a matter of sur
prise II a large vessel, freight or PASSENGER
should find something the Michigan over
looked. Mr.. Wilson says that unless an ex-
act Typographical chart of every acre Of
harbor Is made, it cannot be relied unon
| conclusively- Yet the charts made are
| SO fully that changes from the depths
| marked In detail are not probable
AS soon as an obstruction is located and
|
and all about for long distance to deter
mine its extent and the possibility of its
oeIng one OF group. These new charts
are aht ISSUED as soon as completed and every
OF course, in the lakes. where shore lines
are so close, sailing by the compass ia not
| so exact as IT Is at sea- Still masters are
expected to be able to do this whenever
called upon In lake charts however. Oh
| structions are plated both by latitude and
harbors nearest al hand.
no system or lakes presents as wide vari-
atoms OF extreme depth as the big fresh
water system. Beginning with Superior ami
following the chain eastward they vary
from 1856 feet to but 21O They are re-
spectively 6G2 feet above the sea level for
superior 1 .,sl each for Michigan and Huron.
ol3 for Erie and but PAT for Ontario. Supe-
rior is far the deepest, with Michigan sec
ond ontario Is close on It's heels being
W ntn lew feet OF Huron, while Erie is 81
shallow that Its greatest depth is thirty-six
rect less than the midlake depth Of M CHI
1gan between Chicago and ST. Joseph. Erie
can claim but 21o feet extreme depth
AS good a object lesson of what the Ia kes
nave to offer Is the course between Chicago
and St. Joseph. Mich. The course is meas
R uIed from me me lights OF the two harbors.
Beginnlng from this side the government
pier. already quite way out, has a denth
of some thirty-sfx feet. The lake shoals on
TINS slde so That the extreme depth of the
spoon IS trihe beyond the middle of the
nifty -seven-m mile course. 1t drops rapi6lv
however, from sixteen in the river to 81;
OUT IN the lake. But on the other side
I within couple of miles of the shore, the
depth drops from twenty four feet to 1G6
with frightful rapidity. BY the time the
second song is sung leaving ST Joseph the
singer Is over some forty fathoms of water,
Superior, if reduced to the sea level vouId
be robbed of two-thirds Of its dimensions
The extreme depth is well east of the mid
die line Michigan has her greatest denth
1000 feet up. toward the straits. Huron is
less than 500. while Erie is very shallow
ontario has depth Of 1856 feet owing to the
ralis OF Niagara If all were brought to
sea level, Erie would be 500 feet shova
Michigan would be couple of ponds. Hin,
ron almost out Of it. Superior a lake not
much larger than many another and On.
tario the largest of the system