Evening star. [volume] (Washington, D.C.) 1854-1972, 1857-02-13

the river. There are twelve of these spans
tsee drswing) admitting the entrance-free
passage and exit of the canal underneath.
Inns superstructure is calculated to sustain
SIX times the greatest passing load that can
come upon it-a limit fixed in England by the
highest authority.
The boiler plate girder has been adopted as
being very reliable, presenting great durabili-
| ty, and In keeping with the massive architec,
ture of heavy stone bridge At no point Go
the common road and railroad interfere with
| each other-the former passing under the lat
ter on either shore, while on the bridge par
tition efectually separates the two The
bridge of Bercy, one of the most frequented of
the French capital, presents a striking exam
pie of the success attending this arrangement
Estim ated cost of this bridge. 80. 1892, 1853 90
Add 20 per cent. for contingencies. Ice, 554 90
Total '..'...........'.... 999, 1922 90
1t is not doubted that several railroad com
psnies would be willing to give a large sum
Tor the right of way, thus greatly diminishing
the necessary expenditures on the part of the
| government.
The surrounding country has been surveyed
with reference to railroad connection, and the
only practicable route is traced out on the &C.
| companying map Several lines were rup
with the following results. 1t is impractical.
ole, or at least would be excessively expen.
sive, to pass through Georgetown with a rail.
| road, as, from q thorough examination it is
evident that tunnel, 1000 or 5 900 feet in
length would have to be excsvated the
greater portion in hard sienite, commonly
| called in this locality blue.stOne rock A
comparatively favorable route has neverthe-
less been found. Leaving the aqueduct. i'm
mediately enters q small ravine, from which
it passes by tunnel 500 feet long into the
valley just in the rear of the Georgetown Col
lege; thence, with grade of seventy feet to
the mile 1t ascends to a depression in the
| heiShts OF Georgetown, necessitating a cut Of
over fifty feet, and short tunnel Of 800 feet
Descending again, it crosses Rock Creek,
which it follows for a short distance, finally
| reac hing the commencement of Massachusetts,
avenue A line of levels was run over this
avenue without very favorable results, but
cheap location could be easily found by bear
ing to the north and coming into the Baltimore
and Washington railroad by descending the
Tiber valley.
The distance to the present depot from
common point on the Virginia shore would be
three miles greater by this route than by the
enc over the Long Bridge. But should the
| depot ever be removed to the northern confines
! of the city, and a more direct southern line be
taken from Baltimore, the route by the aque-
duct piers would in that case compete favora-
bly, with any other in every respect; and even
In the present state Of things, obviating, as it
does, the necessity of passing over a draw or
through the built-up portions of the city, it
| presents great and compensating advantages
to be set of against an increase of distance.
A profile and Typographical map of this route
accompanies this report The country around
| Georgetown is very uneven, and the construc-
ton of any railroad through it, although per
fectly feasible, will be necessarily expensive.
| THREE SISTERS.
The locality called the Three Sisters is the
last one upon which it is my duty to report
| minute survey convinced me th at it was but
little adapted to any other than a suspension
bridge.
have proposed two plans-one similar to
the Niagara bridge, with a central supporting
pier the other, but a slight modi fication Of
Mr.. Ellet's design. This design was presented
at time when the Little Falls bridge had
been destroyed; and the reasons which then
| existed for cite so far up the river have since
ceased by the action of Congress at its last
| session, apprOpriating a sum OF S75 600 to
complete the bridge to which reference has
| just been made.
The railroad line which would connect with
the Three Sisters is less favorable than the one
TO the aqueduct. 1t indicates 20 or so feet as
the proper height of the roadway The Vir
ginia shore is rough and elevated, and the
| cost Of approaches on that side would form O
heavy additional item. Estimate for single
span, s443, 900; for bridge with central pier,
4
1t is proper, perhaps, that should here
briefly re capitulate the conclusions resulting
from the foregoing views. The localities pre-
sentlng decided advantages over all others for
permanent bridge are the present site Of the
Long Bridge AID that Of the aqueduct piers
For the general accommodation of the city Of
W ashlngton, and the facilities Of intercourse
with the country on the opposite shore, the
site of the Long Bridge is evidently most ap-
propriate. permanent bridge there, how
ever, is necessarily expensive, and, to avoid
the total obstruction Of navigation, must have
a draw, which is at the same time an inconve
nience both to travel, especially railway
travel, AID to navigation. Every locality be-
tween that and the aqueduct shares in its dis
advantages, without presenting its facilities
The proposed bridge over the aqueduct piers
is more economical, avoids a draw, and ac-
| commodities at the same time the interests Of
navigation and railway travel, and, to a lin
tied extent, local travel also; but as means
OF communication with the opposite shore for
the city of Washington it is altogether defec-
tive.
To provide for all the exgencies of the case
therefore, 1t would seem to be necessary that
both bridges should be eJnstructed-the Long
Bridge ION less expensive scale than that
which has been contemp lated) for ordinary
purposes. and so as not to be inconsistent with
an improved navigation, which is at present
a most urgent want; and the bridge over the
aqueduet piers, for the threc-fold uses Of rail-
road, local road, and canal The cost of the
two thus regulated would not be 80 great
probably, as that Of the Long Bridge alone,
fitted for railway use as we'll as ordinary pur-
poses, involving increased width, much
heavier draw, and more expensive coustruc-
ton Of every kind, while the dangerous acct
dents, and many inconveniences inseparable
from the current use of long and extended
bridge for both railway and common travel
would be happily avoided.
In closing this report, L feel it to be an act
of justice, no less than pleasing tribute to
| all the gentlemen associated with me in a diff
fcult and laborious service, requiring much
application out Of the usual hours of business
in order to meet the wishes of Congress for
report during their present session, to bear my
testimony to the jealous, skillful, and unre-
hitting CO operation of each and all of them
in their respective departments
have the honor to be, with great respect
your obedient servant,
/ ALFRED L RIyEs