The daily banner. (Cambridge, Md.) 1897-2008, 1914-10-03


fair indications of continuance OF
such material. The water in the
sand (called wet SANDY is unques-
tionably ground water, and Will
cause no trouble. Boring No.
shows material that can be easily |
excavated, and the same may De
said of behring's Nos. 4, and o.
While it would have been desirable
to have carried No. down to the
grade of the canal, the fact that
it was not done need cause no ap-
prehension of difficult material be-
ing encountered, for there are many
indications. to the contrary.
The character of the excavations
will determine the side slope. THESE
are usually fixed for such construc-
ton at three base to two vertical IN
ordinary earth. There are 1ndlca-
tions. however, that these slopes
may stand sleeper than that, for
which reason, while the drawings
are made for slopes of three base
to two vertical, and the first esti-
mate is found on this basis, sec
ond estimate is given, based on
slopes of one base to one vertical.
In executing the work, the slope OF
one on one could be tentatively
adopted, and experience will soon
show whether or not it is too steep.
A BERN three feet wide is provided
at a height of it. above low tide.
This need only be constructed where
the cutting is at least IS tt. deep.
The amplitude of the tides in
Chesapeake Bay in this latitude is
only about II #. In strong north
westers the waters of the ay,how-
ever, are blown over to the east
side which may raise the surface
on that side above the normal. But
under these conditions it will be
raised at each end of the canal
at the same time, and of the same
amount, and the difference in level
will not be appreciably affected. Ac-
cording to the statement made by
Mr.. Hatton, the time of high wa
ter in the Black Water river is
about four hours ahead of that in
Cambridge harbor, but the small
amplitude of the tide precludes all
possibility of any damaging current
being developed. Consequently no
lock will be required. The canal
will be plain, open cut.
From Cambridge harbor to Sta.
$3.50 the material should be exca-
waited by means of drag or wheeled
scrapers. This will all be done in
the dry, and the excavated material
deposited on each side of the canal
within easy reach. From Sta.935O
to the south end Of the canal the
material can be most economically
handled by means of a light drau-
ght clam-shell dredging machine,
with a long bone and rather small
bucket. Such machine, however can
not be found less than about 35 tt.
beam. It would therefore be neces-
sary to dredge the cut about As tt.
wide to float her. The material is
quite soft, however, and the excava-
ton easy. The excavated material
would be deposited on each side of
the cut.
There are no less than three brid-
ges, and possibly more, that will
have to be built over the canal. OF
course, these crossings will have to
be provided with draw-openings,
which can be opened to allow boats
to pass, or else the floor of the
bridge will have to be high enough
to allow them to pass under. Draw
bridges not exceeding "a #. open
ing will not be expensive works,
but the matter of opening them on
the approach of boats, for the pas
sage of the latter, is more serious
question. It will require at least
one man to each bridge, who must
be on hand all the time. 1t may be
more economical, therefore,to build
such bridge high enough for the
boats to pass under. Boats having
masts should be required to unship
them in sailing through. No esti-
mate has been made for the brid-
ges in question.
am informed that the waters OF
Cambridge harbor are now contami-
mated to some extent with sewage
from the city of Cambridge, and the
question has arisen as to what eff
feet the canal may have on the wa
ter. To some extent it will be