Evening star., 1916-03-16
|N0FURTHERH HALT
| TO CANAL TRAFFIC
Committee of Scientists
! Evolves Plans to Prevent Ad-
ditionaI Slides at Panama.
EXCESSIVE FALL OF RAIN
HELD CHIEFLY TO BLAME
Date for Reopening for Navigation
Not Set, But Time Is
Not Far Off,

Navigation through the Panama canal
is not likely again to be seriously inter-
rupted by slides, and realization OF the
great purpose for which the waterway
was constructed is assured in the near
future. according to the finding OF a
committee of scientists appointed by the
National Academy of Sciences at the re-
quest of President Wilson to investigate
the problem. While the committee real
ICES that slides may be considerable
maintenance charge upon the canal for
a number of years. it believes there will
be little trouble after present difficulties
have been overcome
A summary of a preliminary report by
, the committee was made public today
at the White House. NO time was set
when the canal can be opened for navi-
CATION. but it was said that this time
is not far off,
Excessive rainfall was found to be one
of the chief causes for the slides and
control of the falling water was the
most important remedy suggested The
committee made detailed recommends
tions for the prevention of slides in the
future.
Authors of Preliminary Report.
Although the committees final report
will not be ready until April. William
II WEIGH. president of the academy, has
transmitted to President Wilson pre-
liminary report of the committee, pre-
pared by Charles r. Van Hise, president
Of the University of Wisconsin, chair
man: Gen. II. l.. Abbott, Corps of Engi-
neers United States Army; John c.
Branner, geologist and former president
of Stanford University; Whitman Cross
geologist in the United States geological
survey: R. c. Carpenter, professor OF
mechanical engineering in Cornell Uni
yersity; Arthur p. Davis, chief OF the
reclamation service, Washington; Johr
R. Freeman, constructing engineer
College of Engineering, Northwestern
| University: Harry Fielding Reid. profes-
sor of engineering, Johns Hopkins Uni
versity.
of the canal with confidence the re
port declares. "It is not unmindful Of
the labor necessary to deal with the
present slides. and it realizes thai
slides may be a considerable, but not
charge upon the canal for number
of years: 1t also realizes that trouble
in the Culebra district may possibly
again close the canal Nevertheless
the committee firmly believes that
after the present difficulties have beer
overcome navigation through the canal
is not likely again to be seriously in
terrupted. There is absolutely no JUS
tifcation for the statement that traffic
will be repeatedly interrupted during
long periods for years to come. The
canal will serve the great purpose for
which it was constructed, and the
realization of that purpose in the near
future is assumed.
"All slide material which reaches the
canal must. of course, be removed at
a certain expense and inconvenience
The engineers estimate that about
100000 cubic yards will have to be
removed between the two Culebra
slides. and the dredges can remove
l.oOo. 900 cubic yards a month. But ii
must not be supposed that the canal
will remain closed for nine months
as soon as the channel has been suf-
hciently deeDened and the movement
of the slides becomes so low that the
dredges. even when interrupted by the
passage of ships, can more than keel
pace with them. the canal NAV be
opened for navigation. This time prob
ably is not far off.
Expect Slides for Years.
The committee believes that some
sliding ground will continue to enter
the canal for several years to come
though in diminishing amounts. Any
relatively inexpensive measures which
tend to arrest the present active slides
or which promise to reduce the charge
against maintenance of the canal in
the future. are therefore fully war
ranted. Es. "a
The composition of the rocks, their
n rll lrrn
are all instrumental in producing the
slides. are beyond the control of man
but partial control of ground and
rain water and the relief of pressure
by unloading certain areas are feasible
1 and the committee confines its remedial
suggestions to these measures
The slides in the Canal Zone are es
| sehtaiiy like many in other parts OF
the world; they are due to the inability
OF the earth or rock to support the
weight of everything material. Slow
processes of natural erosion. rapid cut
ting by flooded streams and excavations
by man frequently lead to landslides
Much OF the canal is cut through weak
rocks, and In the Culebra district the
prism is exceptionally deep.
The rocks of Culebra district are OF
| two kinds-stratiied and massive The
chief material involved in the slides
is the stratified Cucaracha formation
1t Is composed of slippery minerals
which are only weakly CONSOLIDATED
The Cucaracha beds are limited, along
the line Of the canal. to the CuIebra
district. but they have a thickness in
places of over 400 feet. The soft, slip
perry nature of its materials and their
loose. unconsolidated condition make
1t unusually weak and unable to sus.
tain any considerable load
The strength of the Cucaracha clays
is greatly decreased by the presence OF
water, and the heavy tropical rains
keep them nearly saturated the greater
part OF the year: for the broken and
irregular surface of the slides and the
open cracks around their borders greed
them.
In the Culebra district the average
! rainfall since 1914 has been S7.68 inches
per annum. of which about eighty
| inches fall in the rainy season Of about
eight months: Where nearly seven feet
of water fall upon the surface of the
country within eight months of the
year. 1t Is not surprising that there il
difficulty In controlling the under
ground seepage. Indeed, during these
months the ground water table IL prac.