The national Republican. [volume] (Washington City [D.C.]) 1866-1870, 1869-09-30

tion, by IAN act TO alter tho bridge and
draw across tho Potomac, from Washington
7, ,ss A1.a s1asr sgPr0ssd May
q o.! II. &C. r e Tha: the Council shall
intend the health Of the city, to preserve
the nayigation Of the Potomac and Anacos-
TIA fivera, adjoining the city; 10 erect, repair,
and regulate wharyes, to deepen the docks
and basins" &c. The law therefor also
appolnts the proper persons 10 watch over
and preserve the navigation. The question
now ariscs whether the certain repairs being
made on the railroad bridge Wilt have the
effect 70 destroy the channel Of the river, 90
far as tho port Of Georgetown u concerned.
After careful study and consideration Of
the matter, u 10 my opinion that the obstruc.
lions formed By the piles used In the re-
pairs will certainly. Affect, and II may be
very seriously, the channel Of the river. A
very distinguished engineer writes that
"Every obstruction temporarily placed In
the way Of the current, every attempt to
guard one point by any artificial means, In
evitably produces some correspcnding change
at another, which can seldom be foreseen,
and for which the remedy applied may provo
but new cause Of HARM" He continues to
say that emo obstruction should be placed to
tho free ingress Of the tides through all the
channels" am .... TLTT
The many able reports written In years
past generally agrec upon the plan Of re-
moving all obstructlons, even TO the Long
bridge causeway. Colonel Albert, chief Of
the Corps Of Typographical Engineers, re-
ports that this causeway has aided In all the
difficulties concerning the channels, the
tendency to shoallng In all OF them. He
also states "that the causeway Of the Long
bridge Is not the result Of tho plan of any
United States engineer officer, but was
adopted against the advice Of all who were
consulted on that occasion; but the plan
being made positive direction Of law, IL
had to DO pursued In the construction Of the
BRIDGE" The causeway has proven very
great evil, but the injury done should not be
accelerated by further obstructiDg the chan
mel way. Lieut.. Col. Kearney, Of the same
writes as follows: "From tho nature of the
bed Of tho river, yielding as II does under
the action Of q very slight force, II must be
apparent that the depth and course Of the
channels arc not very constant, and accord
ingiy our own observations made upon II,
united with tradition, confirm the opinion Of
extreme vc'lablcness. 1t Is near the middle
channel that, in former days, the river had
worn for Itself tho deepest passage. We
have pene.E led the alluvial deposit to a
depth Of for.J feet at that place. The ac-
usually flows near the city shore, and one,
also, which struck II very obllquely, is
| evinced by tho bluff shores south OF the
Tiber. These observations arc necessary to
demonstrate the extreme care that should be
observed In securing the foundations Of the
bridge, the requisite stability, and the eau
ton with which We should avoid every un-
necessary interruption Of the channel"
From the several reports made BY others
| L. L. o,,kt ha aan aroI
opinion Is that all distractions, whether they
be OF causeways, piles, or any other kind,
excepting only those that are absolutely ne
cessary for the support OF the bridges,
should DO removed so as not 10 Interfere
with the currents OF the river. The Potomac
being tidal river the reasons for doing SO
become still greater; for the same cause, as
we'll as those above stated, all shoals should
be deepened, and such parts Of the different
channels, both above aud below the bridges,
as now tend to arrest the ascent and descent
OF the tidal wave, should be widened. So
important has the subject OF the improve
ment Of tidal rivers become In Great Britain
that commissioners have been appointed to
investigate the whole subject, and to inquire
what measures 1t may be expedient to adopt
for the general improvement Of the harbors
and rivers Of the United Kingdom. The
most stringent legislative measures were re-
commended by the Tidal Harbor's Commits
sion for the conservancy Of the harbors and
rivers. l had the honor, General, on the
30th Of April, 1858, to submit you a report
on the examinations or surveys Of the Po-
tomac river, q copy Of which is contained In
the pamphlet, marked y, (pages 28 to 3o,)
accompanying this paper. In that report
the whole matter Of the Improvement Of the
channels Is discussed. The following are
some extracts from the same; SIN anticipa-
ton Of such Improvements legal measures
should be taken for remedying all existing
injuries to the channels for the conservation
Of tho shores and harbors for preventing
future encroachments in the construction Of
such works as may produce any damaging
effect. Every encroachment should be re-
celyed with the greatest Jealousy"
In speaking OF the removal Of the cause
way, the same report says that "whatever
opinion may DO held or have been expressed
by others 10 regard TO the obstruction or en-
croachment In the river In consequence Of
the building Of the causeway Of the Long
bridge, II has been already demonstrated TO
me that there Is no doubt Of that structure
being very injurious to the Washington
channel, and that the section referred to
should, therefore, be removed and replaced
by either an arched bridge or one on piles of
iron or wood. Those best acquainted with
the river have pointed out most marked
Increase during the last few years in the d.
menslons Of the fats, and q consequent
dlmlnution In the width and depth Of the
channel. Whilst the causeway obstructs, to
considerable extent, the water coming down
from the interior Of the country, 1t also par
TALLY prevents the tide water from flowing
up; 1t therefore interrupts that continual
scour which should result from the force Of
the one and the flowing and ebbing of the
other; the tides should have perpetual and
unrestricted current. THE great object to
be kept In view, In carrying into ell ct the
improvement Of the navigation Of tidal
river, 10 the free admission Of the greatest
possible quantity Of water from the sea, as
reliance must be chiefly placed upon the
scour produced by the tide, and not upon
the current OF the fresh waters as the
chief agent In keeping open the nayigable
channel OF the river Many celebrated en-
gineers have concurred In the above opin-
Ions; and this being admitted, 1T is manifest
that all distractions to theS tidal flow up
wards should be removed such as shoals
and bars, or dams and dikes or any other
that applies to greater evil will apply to
lesser one. 1t would be impossible to asccr-
tain the exact time or estimate the extent of
such damage or Injury, as so many unforc-
seen natural, rs we'll as artificial, causes
enter into the calculation. The only remedy
is to remove as soon rs possible the cause,
II well established, of the evil now COM
planned. Of, and in future to prevent Its re-
currence. The navigation Of tho Potomac
is not thing of to. day, but must live In the
future to aid In the promotion of the enter
prise and enlightenment OF more advanced
civilization and culture; Its channels should
be preserved and guarded with the utmost
care against all entertainments. The prob
lem has always been considered a most un-
certain one, but infinitely more important
and difficult than the spanning of q stream
bya bridge; the latter should aud can always
be built to accomplish its laudable purpose
without interfering with the navigation of
the river II crosses.
am, General, very respectfully, your obc-
dent servant, N. MiCHLER,
Major Engineers, Brcvet Brlgader Gene
cral U. 8. A..
The Georgetown Councils meet tonight,
and 1t Is probable that tho report, as given
above, will be submitted to them by Mayor
swceny, who has received an official copy
from the War Department.
THE NATIONAL IRISH REPUBLICAN Asso-
CITATION meets this evening, at Trades