ier of Spain, forms the boundary of the
two kingdoms to the sea. The area of
the basins of the Guadiana is 25,000
square miles. Although 316 miles in
length, the river is only navigable up to
the town of Mertola, about 40 miles from
its mouth at Villa Beal. The entrance
to the Guadiana is encumbered with
shoals, and at low water there is only a
depth of about 6 feet on the bar, or 18
feet at spring tides. Within the bar,
however, off Villa Beal, where the river
is ^ mile broad, the depth is 27 feet.
The Ebro rises in the province of
Santander,and drains 39,000 square miles,
and after a course of about 470 miles,
empties itself in the Mediterranean, about
15 miles east of the town of San Cirlos
de la Bapita. It receives one hundred
and fifty tributaries, and its chief towns
are Tudela, Saragossa, and Tortosa. At
Amposta, 20 miles below Tortosa, the
river divides and runs into the sea by
two branches. In order to facilitate the
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communication with the sea, a lateral
canal, 1 miles long and 5 feet deep, runs
south from Amposta to San Carlos, at
Port Alfaques, where there is room for a
large number of vessels not drawing
more than 18 feet. The principal com-
mercial utility of the Ebro is the trans-
port of grain from Saragossa to Tortosa,
together with the floating down of timber
from the Pyrenees. Owing to the shal-
low channels of the Delta, however, and
to the numerous sandbanks at its mouths,
only vessels of very light draught are
able to pass the bars, and hence the navi-
gation of the Ebro, although the largest
river in the peninsula, is not very im-
portant. As a source of supply for irri-
gation, however, the Ebro, like the ma-
jority of Spanish rivers, is of more value
in this respect than as a navigable stream.
Its bed is rocky, and its current above
the influx of the Segre, its principal
affluent on the left, much disturbed by
rapids and cataracts: and though this
evil has been remedied in part by the
construction of a navigable channel, the
Imperial Canal from Tudela to a point 20
miles below Saragossa, yet the obstacles
to navigation are still great ; and whilst
its use as a source of supply for irrigation
is increasing, its volume for navigable
purposes goes on decreasing in the same
degree.
Besides the navigable canals connected
with the Ebro, there are only worthy of
special mention the canal of Segovia, con-
necting that town with the river of the
same name, and the canal of Castille, to
unite Santander with the Douro, a work,
however, which is only partly finished.
According to Millet, the total length of
navigable canals in Spain was only 130
miles in 1875. On the other hand, the
length of her railways was 5,600 miles in
lb84.
ITALY.
Italy is not rich in waterways except in
the valley of the Po. The navigable
portions of her rivers — the most im-
portant of which will shortly be described
_have only an aggregate length of 1,100
miles.
The Po rises at 6,560 feet above the
sea, and in a course of 350 miles drains
an area of 29,000 square miles. At a dis-
tance of 20 miles from its source it enters
the plain of Saluzzo, between which and
Turin, a distance of only 30 miles, it
receives three considerable tributaries.
The Dora, which flows past Susa at the
foot of Mont Cenis, imites with the
greater river a little below Turin, and the
Sesia joins it 25 miles below the con-
fluence of the Dora. About 30 miles
still further on, the Po is joined by the
Ticino, which brings with it the overflow
of Luke Maggiore. Its next great af-
fluent is the Adda, which flows through
Lake Como ; then comes the OgHo from
Lakelseo; and finally the Mincio runs
in near Mantua from Lake Garda. At
its confluence with the Mincio, the Po
has a width of from 1,200 to 1,800 feet,
and it then continues to flow on in an un-
divided stream to its first bifurcation
near Ponte Lagoscuro, and thence on to
Maria de Ariano — about 25 miles from
the sea — where it parts into two arms,
and these again are subdivided into
several other branches, forming an exten-
sive delta about 20 miles in width from
north to south. The growth of the delta
since the time of the Romans is very
marked. The town of Adria, which was
then a maritime town, now stands on the
banks of the Po 20 miles inland, and it
has been estimated that from the year
1600 to 1800, the delta advanced at the
rate of 225 feet annually. On the other
hand, to the north of the delta, there is
equally good evidence of the encroach-
ment of the sea on the land.
The Po is continuously embanked from
near Cremona to the marshes at its
mouths. At its highest flood the water
rises 24 feet above extreme low water at
the confluence of the Ticino ; 26 feet near
Piacenza; 20 feet at Cremona; and 28
feet at Ponte Lagoscuro, 4 miles above
Ferrara, where the level of low water is
only 9 feet above the sea, from which the
old city is now removed 50 miles, or 20
miles further from the coast than two
thousand years ago. Hence it is that the
top of the embankments at Ferrara is
higher than the roofs of the houses. The
prevention of the lateral spread of the
water in floods by dykes is said by many
engineers to occasion the deposit of
sedimentin the channel, and consequently
to cause an elevation of the bed, which
requires the embankments to be raised
proportionally; but Lombardini has
shown that the efiect of this on the Po is
by no means so considerable as has been
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INLAND NAVIGATIONS IN EUROPE.
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often represented, and that in the middle
lower course of the river the bed of the
proper low- water channel is subject to so
little permanent change of level as to
have now become substantially constant.
The mean discharge of the Po is 60,745
cubic feet per second, its maximum 181,-
580, and its minimum 7«558 cubic feet
per second, or a ratio of I to 24. The
waters of the Po are very heavily charged
with detritus, and according to Mr.
Boccardo, the volume held in suspension
is at times Tfi^ of the volume of water
discharged.
The Po is navigable from its month
for vessels of 130 tons up to Valenza,
600 feet above the level of the sea, and 7
miles below the confluence of the Sesia,
and below the confluence of the Oglio
the depth of the main river at extreme
low water is never less than 5 feet 10
inches; but as most of the transport
which would otherwise be carried on by
means of its channel is now effected by
railways, of which Italy possessed 5,651
miles in 1883, the river has lost much of
its relative importance as a route for com-
mercial communication.
The Adige rises in the Tyrolean Alps,
and drains 5,400 square miles in a length
of 234 miles. Flowing southward it
passes by Trent, and enters Lombardy.
After passing Verona, it flows nearly
south-east, and pui^sues a course parallel
to that of the Po till it enters the Adria-
tic by an independent mouth about 13
miles north-east of Adria. The waters
of the two rivers have been made to com-
municate by artificial cuts at several
places. The Adige is navigable from its
mouth to Trent, but the velocity of the
current impedes the navigation.
The Tiber rises in the Apennines at a
height of 3,805 feet above the sea, and
drains 6,500 square miles, and after a
course of 240 miles, generally in a south
direction, empties itself into the Mediter-
ranean through two mouths about 16
miles south-west of Rome or 24 miles by
the course of the river. The mean dis-
charge of the Tiber is 10,800 cubic feet
per second, and its minimum discharge
5,800 cubic feet per second.*
* The proportion of the mlnimom to the maximam
flood has been yartoiuly estimated by Italian engineers
as belnjir from 1 to 25 to l to 80; or from a minimum
disoharffe of 8,000 cubic feet p^r sroood to a maximum
of 106.000 cubic feet. According to Mr. Vescovall. the
discharge of the Tiber has never been less than from
fi«600 to 6,800 cubic feet per second.
Bozet has calculated that the advance
of the delta for many centuries past has
kept steadily at the rate of 13 feet per
year. The estuary, which originally
formed the harbor of Home, was so re-
duced in depth by silt from the river and
sand rolled in by the sea, that it was
found necessary in the days of the Em-
pire to cut a channel from a point about
1^ mile above Ostia (the ancient sea-port
of Eome, and now 2^ miles inland) to the
coast, at a place called Fiumicino, situated
at 2 miles N. of the chief disemboguement
of the Tiber, now called the Bocca di
Fiumara. The artificial canal— known as
the Fiumicino branch — (on the north
bank of which are the remains of the once
famous ports of Claudius and Trajan) is
still the only navigable channel between
the Mediterranean and Bome, the old
Fiumara mouth being obstructed by
constantly-shifting sandbanks.
The rise of the Tiber in its great floods
is very considerable, and is measured
from the zero of the hydrometer at the
Bipetta stairs at Bome. This zero is 4
feet above the level of the sea. The
lowest known surface of the Tiber at the
stairs is 17| feet above zero, and its mean
height 22 feet In the inundation of 1870
when I was on a visit to Bome, the
waters rose to 56 feet 6 inches above
zero, and as the pavement of the Bipetta
and that of the adjacent streets is only
about 44 feet above zero, all the north-
west quarter of the city, including the
Corso and other important business
streets, was overflowed, to a depth near
the river of about 12^ feet, and the direct
and indirect damage occasioned by the
flood, which was the greatest on record
since 1637, could hardly be over-esti-
mated. Numerous schemes have since
been proposed to prevent the recurrence
of a similar disaster. Grave objections
have been made to many of these projects,
but on one point all engineers seem to
agree— and this principle is now being
practically carried out — the expediency
of widening and straightening the channel
at various points within and near the
limits of the city, of carefully regulating
the outflow of drains into the river, and
of removing from its bed the numerous
artificial obstructions, chiefly piers of old
bridges, and accumulated rubbish of
centuries.
The Tiber is navigable from the sea to
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VAN NOSTEAND'S ENGINEERING MAGAZINE.
Borne for Tessels of 140 tons, and, with
some difficulty, 60 to 70 miles further for
vessels of 60 tons. At the Fiumicino
mouth of the river the entrance is nar-
rowed between parallel piers so as to in-
crease the scpur over the bar, but the
available depth on it is rarely more than
from 6 to 8 feet
The Italians were the first people in
Modem Europe who attempted to plan
and execute canals. As a rule, however,
they have been principally undertaken for
the purpose of irrigation. The total
length of the navigable canals is 435
miles. The most important are the Canal
Cavour, in Piedmont, which, supplied
from the Po, begins at Chivasso and
terminates at Turbiga, a distance of 52
miles; the Grand Canal, in Lombardy,
supplied from the Ticino, near Tornaven-
to ; the Canal of Pavia, also supplied from
the Ticino, and passing through Binasco ;
the Canal of Martesana, which, from
Milan through Qorgonzola, leads to
Cassano on the Adda. The provinces of
Polesina in Venice, of Padua, and the
Emilia have all excellent canal systems.
In Tuscany the most important are those
of Pescia, Pisa, and Ombrone.
AUSTBIA-HUNaABT.
As the highlands of Austria form part
of the great watershed of Europe which
divides the waters flowing north into the
North Sea or Baltic, from those running
south or east into the Mediterranean or
the Black Sea, all Austrian rivers of note
flow either north, south or east. All her
great river mouths, moreover, are situated
in other countries, and one of them, the
Danube, has its source as well in a
neighboring State. The courses of its
chief streams, namely the Dnieper, the
Vistula, the Oder, and the Elbe, have al-
ready been summarily passed in review,
and it therefore only now remains for me
to describe the course of the Danube to
complete the list
THE DANUBE.
The Danube is the largest river in
Europe as regards volume of discbarge,
but is inferior to the Volga in the length
of its course and the area of its basin.
It rises in the Black Forest at an eleva-
tion of about 3,600 feet above the sea,
and drains 316,000 square miles, its total
length being 1,750 mUes.
From the mouth of the Iller, which
divides Wurtemburg and Bavaria, the
Danube is fed by at least three hundred
tributaries. On the right bank, the chief
of these, with their drainage area in
square miles, are: the Inn (9,600), the
Drave (14,300), and the Save (37,600),
and on the left bank the Theiss (60,000),
the Olta (9,000), the Sereth (18,000), and
the Pruth (10,000). Together, these
seven streams have a length of 2,900
miles and drain one-half of the whole
extent of the Danube basin.
UPPER Ain> MIDDLE DANUBE.
The upper part of the river first be-
comes navigable, for flat bottomed boats
carrying 100 tons, at Ulm, 130 miles from
its source, and only a few miles below
the confluence of the Dler, its first tri-
butary of any importance.
At Kelheim, half way between Ulm and
Passau, the Danube communicates with
the Rhine by means of the Ludwig Canal,
and the rivers Altmiibl, Begnitz and
Main. The canal is 110 miles long and
7 feet deep, and was completed in 1844
by King Ludwig the First of Bavaria.
From Ulm to Passau (220 miles), at the
mouth of the river Inn, which doubles
the volume of the main stream, the
Danube traverses the great Bavarian
plain, but thenceforward it flows through
a mountainous region till it reaches
Vienna. In this distance of 406 miles of
the lower section of the Upper Danube
the river has been considerably improved
by works of correction, and vessels draw-
ing 4 feet can now navigate the whole
distance at low water, excepting at the
Fischament-Theben rapids, where the
depth is occasionally reduced to 3 feet.
At Vienna, which is situated on the
right and left banks of a branch of the
Danube (164 feet wide and 4 feet deep
at low water) at an elevation of about
520 feet above the sea, and at a distance
of 1,208 miles from the Sulina mouth,
the main stream of the river has been
brought 1^ mile nearer to the city by a
new channel 10 miles long, 1000 feet wide
and with a depth of from 10 to 12 feet be-
low ordinary low- water level. This great
cut involved the removal of 12,000,000
cubic metres of sand and gravel, and,
with all its subsidiary work, cost £3,250,-
000. The enterprise was established by
an Imperial Commission in 1866, and the
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INLAND NAVIGATIONS IS EUROPE.
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proposal to coDstmct the regulation on
its present plan had the able support of
Mr. James Abemethy, Fast-President
Insi O.E.
The cutting has been very successfully
carried out, and has already been of great
service, not only in protecting Vienna
from disastrous floods, the principal ob-
ject of the scheme, but in improving the
railway communications and the navig-
able capabilities of the river at this por-
tion of its course.
Further particulars of this interesting
river diversion, written by the Engineer-
in-Chief, Herr Von Wex, are published
in our Abstracts of Papers in Foreign
Transactions.
The construction of a deep canal, about
150 miles long, from a point on the left
bank about 6 miles below Vienna, to
Oderburg on the river Oder, has lately
been under serious consideration, and the
execution of this project bids fair to be-
come an accomplished fact at no distant
day.
From Vienna the Danube flows east for
150 miles through a wide expanse of
plain country to Waitzen ; and then turn-
ing south pursues that direction through
the great plain of Hungary by numerous
windings to Esseg situated at the conflu-
ence of the Brave, 347 miles below
Vienna, and 165 miles below Buda Pesth.
This imposing-looking capital of Hungary
is situated on the right and left banks of
the Danube at 182 miles below Vienna,
152 below the confluence of the March at
Theben, the frontier of Austria-Hungary
on the left bank ; 146 from Pressburg ; 89
from GK)oy6 near the confluence of the
Baab ; and 21 from Waitzen. From Es-
seg the river trends south-east to Semlin
(140 miles), the lower frontier town of
Hungary on the right bank at the conflu-
ence of the Save, and immediately oppo-
site Belgrade, the capital of Servia.
Hence to Old Moldova (76 miles), and
then on to the Hnngarian-Boumanian
frontier at Old Orsova (63 miles) the
river flows nearly due east. At Old Mol-
dova, it enters a series of rocky gorges,
unequalled in Europe for their grandeur ;
and after sweeping through a succession
of deep pools and shallow rapids, con-
fined within the grand passes of Stenka,
Izlaz, and the Kasan, finally reaches its
last and most formidable rapid called the
"Iron Gates," 632 miles from Vienna,
and 582 miles from the Black Sea.
Although the Danube, from Vienna to
Old Moldova, has also been regulated in
numerous places and at great cost, by
narrowing and training works, consisting
of groynes, dams, and longitudinal dykes,
there has been but little appreciable im-
provement effected in its general navig-
able depth. On this account, projectp,
having in view the permanent acquisition
of a sufficiently wide channel of from 6 to
8 feet deep at every point between Pas-
sau and Old Moldova, have lately been
prepared by Government Engineers,
which involve an outlay of £2,000,000 to
effect the desired improvements, the
principal of which would be the perman-
ent removal of the Fischament-Theben,
and the Fressburg-GK)nyo shoals.
With the exception of a short stretch
of the river near Gonyo, the existing
channel between Vienna and Old Moldo-
va, affords a minimum depth of from 4 to
5 feet, during nearly two-thirds of the
year (taking the ice into consideration) ;
but at Gonyo itself, the navigation dur-
ing the dry season is so difficult that a
depth of from 3 to 5 feet is only main-
tained by Mr. Murray Jackson's excel-
lent system of steam-raking, a full
account of which will be found in our
Minutes of Proceedings.
The Danube between Old Moldova and
the Iron Gates (69 miles), 6 miles below
Orsova, the frontier town of Hungary, is
traversed at eight different places by reefs
of sharp-pointed rocks, which render the
navigation difficult at ordinary low water,
and altogether impracticable at the lowest
water season. These serious natural ob-
structions have hitherto been the great
barrier to the free development of traffic
on the middle and lower Danube, and the
existing slackness of trade at this part of
the river will continue, and possibly in-
crease, until its navigable condition has
been radically improved. These so-called
Cataracts of the Iron Gates, which are
wholly within the temtories of Rouma-
nia and Servia, have a length of 5,070
feet, with inclinations of 1 in 507 at high,
and 1 in 307 at low, water ; the extreme
variations between high and low water
being 14 feet 6 inches at the head and 22
feet 6 inches at the foot of the falls. Tlv)
level of low water at Old Moldova is *20l
feet, and at the foot of the Iron Gatcs^
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VAN NOSTRAND'fa ENGINEERING MAGAZINE.
118 feet above sea-level. This fall of 83
feet in 69 miles gives an inclination of 1
in 4,400, as compared with 1 in 2,220 be-
tween Passau and Vienna, and of 1 in
10,000 between Vienna and Old Moldova.
For more than a quarter of a century
projects have been made for surmount-
ing the difficulties between Old Moldova
and the foot of the Iron Gates, by four
different systems of treatment, namely,
by open cuts ; by simply narrowing the
channel ; by excavated channels confined
within submerged and insubmergible
walls; and by a combination of one or
more of these plans, aided by one or
more lateral cancds.
The latest project is that of an Inter-
national Commission of Engineers named
by the Austro-Hungarian Government in
1879. This Commission proposed to es-
tablish a channel 2 metres deep at ex-
treme low water, at every point between
Old Moldova and Turn-Severin by means
of cutting 60 metres wide through the
upper seven shoals, and to construct a
lateral canal at the Iron Gates on the
Servian shore, provided with two lift
locks (508 feet by 118 feet) Co overcome a
difference of level of 14 feet 6 inches at
that place. The cost of the open cuttings
was estimated at £350,000 ; the improve-
ment of the Iron Gates at £530,000.
The width of the Danube between
Vienna and Basias (15 miles above Old
Moldova) varies from 2.000 to 6,000 feet
at low water, and from 7 miles to 30 miles
at high water ; but to this statement ex-
ception should be made of Peterwardein
(50 miles above Belgrade), where the en-
tire volume of the river, at high and low
water, flows through a channel 40 feet deep,
and only 800 feet in width. At this
spot, 777 miles from the Black Sea, the
Danube is crossed for the last time by a
railway bridge, or, indeed, by a bridge of
any kind whatever. At the Kasan, a
pass 5^ miles long, where the granite
cliffs rise to a perpendicular height of
nearly 1,000 feet, and where the depth
is 80 feet in the dry season, the main
width of the river is but 600 feet, and
the difference between extreme high and
low-water level as much as 23 feet. The
mean velocity of the current from Vienna
to Basias is 2 knots an hour, and 3
knots at high water, but at the narrow
defiles of the Easan and Izlas it attains
8 knots at high floods.
The Hungarian central section of the
river is fed by the Drave, the Theiss, and
the Save.
With regard to the Save and the
Drave, I have only time to remark that
their improvement has never yet been
attempted ; that the former is navigable
in its natural state to the confluence of
the Mur (150 miles), and the latter to
Sissek (370 miles), and that their lengths
from their sources in lUyria to Eeseg and
Belgrade are 434 and 535 miles respec-
tively.
I'he Theiss, or Tisza, falls into the
Danube on the left bank, between Peter-
wardein and the confluence of the Save,
and is navigable for a length of 475 miles
to Tokay. It woiild require the time
allotted for a whole lecture to give any-
thing like a detailed description of this
remarkable affluent, and therefore, in the
few minutes at my disposal, I can only
sketch its chief characteristics in the
briefest possible manner. It rises in the
Carpathians, and its basin drains one-
fifth of the great valley of the Danube.
Half a century ago it had a total course
of 828 miles, and from Tisza Uylek,
where it ceases to be a mountain stream,
and enters the great Hungarian plain, a
course of 750 miles. The length of its
valley from Tisza Uylek is only 372 miles,
so that, like the lower Seine, its length
was double that of the plain through
which it flowed. From Tisza Uylek to
Szegedin (621 miles) the fall was 136
feet in 621 miles, or 1 in 24,500 ; and
from Szegedin to the mouth of the river,
129 miles, only 8 feet, or 1 in 73,000. Be-
tween 1832 and 1879 the cut-offs exe-
cuted by the Government for the piinci-
pal purpose of protecting the adjacent
lands from inundations, were one hun-
dred and thirteen in number, of an ag-
gregate length of 83 miles. These cuts
shortened the river 300 miles below Tisza
Uylek, and cost £690,000, exclusive of
a further sum of £2,000,000, which was
spent by local companies on 1,000 miles
of embankments. According to the re-
port of Mr. Herrich, Ministerial Council-
lor, the result of these great works has
been to protect an area of 4,200 square
miles, out of a total area of 6,000 square
miles of low ground, from floods; but
from no authority can I glean any infor-
mation concerning the effect of the cut-
offs on the navigable condition of the
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riyer. Unfortunately, however, one fact
is but too well known, namely, the great
disaster of 1879, when the large town of
Szegedin, at the confluence of the river
Maros, was almost totally destroyed, and
many of its inhabitants swept away by
an unpreceden tedly heavy flood. It should
be added that the Maros enters the Theiss
at a bad angle, and has also been greatly
reduced in length — ^from 430 miles to its
present length of only 162 miles.
The two chief canals in Hungary are
the Bega, 75 miles long, joining Temes-