Evening star., 1903-07-01
COAST LEVEL CHANGES
SUSPICIOUS THAT BOSTON AND
CHICAGO ARE BEING SUBMERGED.
Alterations in the Continent Which
Have Been Observed by
Geologists.

From the New York Tribune.
A suspicion that the site of Boston Is
slowly sinking has been excited by a civil
engineer named John r. Freeman. While
engaged in making surveys for the pro-
posed Charles river dam last year, he
reached the conclusion that the general
level Of the city has sunk about nine or
ten inches in seventy-two years, and that
the subsidence amounts to an eighth OF an
inch year, or trifie over foot In
century. He depends In part on observa-
tons made at the Charlestown navy yard
where the drydock stills. he says. are nine
inches lower than they were in 1880. Ger
tain rocks in the harbor also appear to be
submerged that much more than formerly.
AS yet the United States coast and geo.
detic survey, which directed a preliminary
investigation of the matter by H. L. Ma
rindin, Is not convinced of the accuracy of
Mr.. Freeman's findings. Its agent calls
attention to the fact that one of the
benchmarks, reference standards has
in some way been lifted out of its original
position, and would give misleading indica-
ttons when comparisons are made with 1t.
He also remarks that the natural settling
of the made land In the Back Bay region
Of Boston would partially explain some of
the observed facts For the present, there
fore. the question of the situation in that
city must be regarded as still open. Fur
ther observation there and elsewhere along
the coast must be made before the truth
can be fully known.
Ages Ago.
In past ages, the biologists declare, vari
GUS alterations of level have occurred on
the continent. Millions Of years ago, for
instance. the greater part of New York
state was under water, and the Adiron-
dacks and a certain great uplift, of which
the Atlantic Highlands are a remnant, were
mere islands. The Catskills are composed
largely of a sandstone that had a sub
marine origin. Then came a period when
this vast area was raised to higher level
than 1t now occupies, and subsequently
other subsidenceS occurred. The Hudson
was once obliged to travel much further
than 1t does now to reach the ocean. BY
the sinking of the land along the New Jer-
sey and Long Island shores the sea crept
further inland. The bed of the old channel
can now be traced under water out for 1O.;
miles, according to United States coast
survey expert, having width of a mile or
two and a depth of 24OO feet. One of the
many consequences Of that general move
ment was that the Hudson is now an arm
Of the sea, not river in the strict sense
OF the term. A tidal flow is discernible all
the way up to Albany.
Whether change of the same nature is
still In progress is, of course. another ques-
ton. Still, there is some reason to think
that such Is the case. Cook, in several of
the New Jersey geological reports, ex-
pressed belief to that effect. Tarr, in his
Physical Geography of New York" quotes
him with apparent confidence Cook
thought that the subsistence was going ON
at the rate Of two feet a century, or nearly
twice as great as that which Freeman a.
signs to Boston.
Tilting of the Continent.
curious fitting Of the interior Of the
continent. in the vicinity of the Great Lakes
appears to have been going on during the
last century. This may be related to the
other movements here referred to- or en-
tirely Independent of them. but there seems
to be little doubt as to It's genuineness AS
long ago as 1869 surveyors noticed that
millrace on the north shore of Lake Su-
perior had run dry, while streams on the
south shore appeared to be growing fuller
near their mouths, even when there had
been no excessive rainfall. 1t was also
discovered that certain natural terraces
along Lake Ontario. which were level origi-
nally, were higher at the eastern end than
at the western. These and similarly sug
gestive circumstances inspired Prof. c. K.
Gilbert Of the United States geological
survey to undertake special investiga-
ton.
Data for eight different stations in Can
ada and the United States reaching back
from twenty to forty years. were secured.
end interesting comparisons made. Rela-
lively to- Port Colborne, on the northeast
found to be sinking at the rate of two
and seven-eighths inches in thirty-seven
years: and Milwaukee seemed to have sunk
two inches in twenty years, as compared
with Escanaba, near the northern end OF
Lake Michigan.
Gilbert was thus led to believe the north
eastern part of the region covered by
these observations was rising, while the
part was sinking. From these
revelations, he computed that there was
rise of water at Duluth amounting to six
inches a century, and in Chicago Of about
nine. In the former place a change of
that character might go on a long time
without doing harm, because the Zenith
City of the Unsalted Seas" is built on a
hillside Chicago's unfortunate fiatness
exposes her to peculiar danger. In fifteen
hundred years she might be ten or twelve
feet under water. At still later period,
Gilbert fancies, the whole chain Of Great
Lakes will discharge into the Illinois and
Mississippi rivers. At that time-say, from
:, 900 to 5000 years hence-Niagara will run