The west shore., August 01, 1886, Page 252, Image 22

252
THE WEST SHORE.
(Inflecting their course, bo that the halves of two waves
tnwt miilwny letween two pontoons, and spend their
momentum in the concussion of their equal forces. The
inventor supposes one line of pontoons is sufficient, but
if, in practice this supposition should prove erroneous,
w;oonJ uiiJ a third lino may bo used. I am inclined
to believe that two or three linns of small pontoons
would Iw more economical in maintenance than a single
line of large ones, while equally effective of the object
sought Tho small pontoons would be less liable to
drag their anchors or go adrift, and would have lens
ability to injure vessels colliding with them than the
larger ones. I quote hore the claims made for this do
vice by its inventor, Mr. E. C. Oreenway Thomas:
1. CompariHrr w,nri7i7ii7ity. Meeting waves
and currents, not with one long, unbroken front, as is
the ease of most break-waters and harbor works, but in
detached xrtions, and not resisting, but cleaving and
evading the force of the waters, it is less likely to be in
jured by violent storms.
2. Economy in Manufacture. )uiu constructed of
few and simplo park, alTccting only tho uper part and
not tho whole depth of tho water, and covering but a
small jiortion of the area it alTocts, it will cost less in
manufacture than any other break-water known.
3. Economy in ronlvucl ion. As it ran be put to
gether in a short time, and anywhere, and no work be
yond that of mooring need le executed on tho Bot
where it is required, there will Iw no necessity for the
employment in si'it of an engineer or other expensive
skilled hilxr, and the usual costs of construction aro
thus very largely avoided.
L Economy in conveyance, l'arlnhilily. -Tho parts,
when taken to pieces, lying flat umii one another, will
occupy small space, weigh little, and can I easily and
iuetHnsively conveyed by land or sea.
5. It is available in exposed positions, where the
continued violence of the sea greatly impedes, and, in
fact, almost renders imixwsihln, the roimtruction of any
other form of harbor work, but where a short time would
auflie for the putting down of the Groenwny break-water,
which is taken ready made to the spot.
ft. It can Iw kept in ttoro in any quantity at any of
our naval arsenals for any length of time, and will thus
l in readiness for any emergencies.
7. It is availablo in any depth, thus rendering easy
the o instruction of shelter harlors iu deep water, with
nccest during all tides. It might lxi used in one long
line of defense fur many miles of endangered coasts.
Filially, it is claimed that it will not cause the accurau
mutation of silt, and thus ruin tho port it is intended
to benefit, as has been the case with many exsnsive
constructions.
Assuming that the Ureenway break-water will pro
duce tho useful rftVU claimed for it, it would also pom
cm many other advantages, aiuougst them the follow,
ing: the positions of tho pontoons could bo shifted as
dofii'U iu their opuraliou were noted, tho lines being
doubled or UellcJ at tho more exHwed points, and
spread out where loss resistance was encountered. Ves
sels could go through very much smaller openings than
those required in break-waters of solid materials, as col
lisions would not bo fatal The openings, being so much
narrower, could be more numerous, and situated so as .to
facilitate the entrance of vessels from any direction. A
disabled vessel could even drift through the line of pon
toons to a position of safety behind them, without suf
fering irreparable injury.
The next great difficulty met with in navigating the
Columbia is encountered one hundred and sixty miles in
land, at the Cascadea The project of a canal has been
wisely adopted here, and ia in such a forward state, that,
according to the report of Major W. A. Jones, U. S. en
gineers, with sufficient appropriations, it could be opened
for traffic within two years. After the completion of the
canal, the other difficulties at the Cascades can be over
come by the use of steel cables, as hereinafter described.
At the Dalles, two hundred and twenty miles above
the mouth of the river, exist the most serious obstruc
tions yet encountered. A canal at this point has been
rejected by engineers as practically impossible, on ac
count of the immense cost and the very long time re
quired for the completion of the work. The next
scheme would be to warp boats through by means of
steel cables, first having removed dangerous obstruc
tions by blasting. I believe there is a probability that
this might be accomplished. Boats have been repeat
edly taken downward under Bteam, without accident, and
I claim that this fact alone raises a strong enough pre
sumption of the feasibility of the cable system, to justify
a particular examination of the river on that theory. If
navigation through the Dalles could bo secured for only
a few months in the year, during medium stages of
water, simultaneously with the opening of the locks at
the Cascades, it would prove of universal benefit to the
uper country. If a careful survey, made by men who
fully appreciate the importance of an open river, and
who aro vitally interested therein, should determine that
the obstacles to tho use of cables are insurmountable,
then it seems to mo that the scheme for a boat railway
presents the cheapest and quickest way out of the diffi
culty. I feel certain that any plan which proposes to
accomplish less than the transfer of loaded boats, how
ever attractive it may be in theory, will bo found insuf
ficient in practice. Flans for the boat railway, with de
tail drawings and estimates, have been made under the
direction of Major W. A. Jones, U. S. eugiueers, and aro
exhibited in executive document number one hundred
and fourteen, firet session of the forty-ninth congress.
Tho scheme involves two systems of inclines, one at Ce
lilo falls and one at the Dalles proper. The cost is esti
mated at one million three hundred and seventy-three
thousand dollars. As Major Jones puts this project for
ward for "agitation and discussion, refraining from rec
ommendation until it has been discussed and treated in
flie usual way," he would doubtless be glad to hear sug
gestions iu regard to the same from persons whose in
terests are affected.