The Sun.
London, England, 1848-04-21 00:00:00

S 117 N
APRIL 2

INSTITUTION OF CIVIL ENGI-
NEERS, APRIL 11.
(Josuui FIELD, Esq., President, in the Chair.)
The paper read was the second part of a commu-
nication male in the year 1841, descriptive of the
Bann Reservoir, county Down, Ireland, by J. F.
Bateman, M. Inst. C.E.
The first part, of which a short abstract was read,
gave the object of the construction of these
reservoirs, which were undertaken with the
view of regulating the quantity of water in the
River
Bann, and more, effectually supplying • water
power to the flourishing and increasing e.tablish-
ments-on its banks. This river is, from the bare and
naked character of the tMourne mountains,
its among
which it rises, s,naturally liable to the greatest irregu-
larity involume; devastating floods frequently
pour down the chancel, where a few hours previously
there was not sufficient water for agricultural pur-
poses—greatly injurious as this must have been to
the agriculturist, it was infinitely more so to the
millowners, who depended entirely upon water power
for their manufactories.
Mr. Fairbairn was consulted on the subject. He
examined the loeality, and advised the formation of
reservoirs. The author was then appointed the
engineer, and acting in some degree upon the sugges-
tions of his predecessor, whom he continued to con-
sult, the works were undertaken which are described
in the present paper.
The peculiarities in the Act of Parliament, granted
in 1836, constituting the proprietors of the mills a
joint-stock company for the formation of the Bann
Reservoirs, are detailed.
The works were originally intended to have been
more extensive than have been really executed. The
reservoir at Lough Island Reary is alone described ;
the ground in that spot was adnairaby adapted for the
work, beings-the bottom of a— brain which was
bounded on all sides by rugged hills of granite ; in
the centre of the basin was a small lake, at the
bottom of which was discovered a bed, several feet
in thickness, of fossil confervm, similar to those dis-
covered by Professor Silliman, at Massachusetts,
North America. This interesting geological fact
was first noticed by Dr. Hunter, of Bryansford ; the
conferne appeared like an impalpable powder, but
when viewed through a powerful microscope, they
were found to be regular parallelograms, many of
them covered with striae. They are described by
naturalists as the fossil skeletons of minute vegetables.
The situation fixed upon for the reservoir rendered
necessary the construction of four embankments be-
tween the hills, so as so raise the water to a height of
35 feet above the summer level of the lake.
The particulars are also given of a series of obser-
vations with rain-gauges, continued for two years,
for the purpose of furnishing data for computing the
extent of reservoir which would be necessary to in-
sure a supply of water throughout the year.
The continuation described the subsequent works,
which consisted of the Corblet Lough Reservoir,
which was designed as an auxiliary pound to receive
the flood waters of the lower part of the river, and to
retain the night water, to be discharged again during
the day, immediately above the more extensive mills
on the river.
A water-course of considerable dimensions was
constructed to effect this, and an embankment was
thrown across the narrow outlet of the lake, the
water being admitted through self-acting flood gates,
which closed as soon as the lowering of the river
created a current in the contrary direction. The details
of the construction of all these works were given, and
it was shown by calculations based upon actual ex-
periment and observation of the quantity of water
received, stored, and delivered from the reservoirs,
that their construction had increased the value of the
mill power of the River Bann full fivefold, at a com-
paratively very insignificant cost, as the actual
expenditure for the works at Corbet Lough did not
exceed 3,3001.; the closest economy consistent with
the efficiency and durability of the work being rigidly
kept in view, and the utmost attention being exercised
by the resident engineer, Mr. W. L. Stoney.
The paper announced to he read at the meeting of
Tuesday, April 18, was " Observations on the Re-
sistances to Railway Trains at different Velocities,"
by Daniel Gooch, Esq.
At the last meeting of the institution the second
part of Mr. Jackson's paper " On the Engineering
of the Rhine and the Moselle" was read. It
consisted to considerable extent of a translation of
an accouLt of the spurs, groynes, and other works
on the Moselle for restricting the dimensions of
the bed of that river, and increasing the depth of the
water, so as to enable the navigation to be carried on,
which would otherwise be averted in the low-water
seasons. It was shown that to effect this nume-
rous arms of the river had been dammed across and
allowed to silt up, the course had been straightened,
elbows had been cut off, and the convex shores, after
being silted up by deposit between the groynes, were
defended by arming of facines, &c. Division- banks
had been established fer inflowing rivulets so as to
carry the gravel to greater distance down the
stream. Rocks also were removed by powder,
and general improvements to such an extent were
executed that the river was comparatively under
good control. The account of the Rhine was then
resumed, and after the various plans that had been
proposed for ameliorating its course, giving nume-
rous interesting and valuable tables of Blankins and
Bolstra's experiments as to the tides, the inclination
of the bed of the various rivers, the duration of the
ebb and flow and average height of the river at the
time of new and full moon, the height of various dykes
above the extraordinary flood line, &c., the paper
finished with these general views—" On looking at
the map of Holland, and tracing its various streams,
it certainly does not appear singular that frequent
stoppages should take place in that country,
whilst such occurrences are comparatively rare
in Germany; for, as long as the Rhine re-
tains its single course as at Emmerick, no ob-
stacles, excepting elbows, stay the progress of the
current seawards; but, as soon as it divides at the
Waal and Pannerden Canal, the evil commences and
increases, according to the number of arms and oban•
nets lower down.
It .
should have generally agreed that a river
more effectually
outlets as possible, in order to
allow it the to clear itself, and that
the tide should be admitted as far as possible,
whilst, at the same
_time, the action of the winds
should be
di
the surface watershed ; again, that the more
any river is abstracted,
the more quickly ° f
the sand will accumulate ;
and also that if a cut be made, it is usual for
ice stoppages to take place below .it, so as to raise
the water level_ above ; and it is also agreed that
if a cut be made as capacious as the river itself,
or be permitted to increase to that extent, it will
soon get beyond co_ntrol, whilst the sand will accu-
mulate rapidlthe ice get y
;
and that when openings exist in dykes
into eddies, loses its velocity, and by
degrees closes up the passage below the opening, so
as to raise the water above. Thequestion therefore
to be solved with regard to Holland and the system
followed there, in order to prevent breaches in dykes,
and to save the better part of the country (taking into
account its creak, marshy soil, and its incapacity to
withstand any great force), is whether it be the better
plan to relieve the pressure on the dykes by cuts and
new channels, and local floodings, at the expense
of increasing the number of ice stoppages, and at the
same time diminishing the velocity in the main river,
thereby greatly augmenting its liability to accumu-
lating sand. It is true, as already stated, that the
rivers are at present in such a condition that it must
be very extensive to effect anything of; importance,
but the question is of such vital importance to the
port of Rotterdam, and the certainty of the mouth
of the Meuse at the Brielle, in the course of
time, closing up like that at Katwyth, if no im-
provements be attempted, is so clear, that it is very
much to be regretted some steps have not been taken,
ere this, to prevent so great a flow of water passing
out by the Holland's diep to Helvoet." The author
directs the attention of the institution to this
subject, and submits the following points for the
consideration of the members :—That the object
to be aimed at in any steps which might be
adopted for improving the Meuse at Rotterdam,
should be to protect and strengthen the shores and
dykes likely to be operated upon by the alterations;
to straighten all the curves on the leek, so as to lessen
chances of ice stoppages; to separate the Waal and
Meuse waters as much as possible, and to lead off the
former, together with the leek, into the sea, by the
Brielle; to narrow the Bresbosch channel (now divided)
into one, regulating the quantity of water • to close
the Krabbe, the Noord, and the Sprey, with sluice-
gates ; and, for the purpose of widening the outlet,
to join the island of Rosenburgh to the main land at
Vlaardingin, thereby causing the ebb waters to act
upon this island, and with increased velocity, and an
additional quantity of water, attempting to remove
the bar and shoals.
At the monthly ballot Messrs. F. C. Penrose, R.
Hughes, H. Currey, F. P. Smith, and S. Woods
were elected as associates.

APRIL 18.
~elosane FIELD, Esq., President, in the Chair.)
The paper of the evening was a series of " Observa-
tions on the Resistances to Railway Trains at diffe-
rent Velocities," by Mr. Daniel Gooch, of the Great
Western Railway. For the purpose of perform-
ing the experiments, a dynamometer was con-
struced at Swindon, in which all the results