Los Angeles herald., 1907-01-13

~ bulIJ but NltlOTlu DHllWdy DTlOHc
oyer the st. Lawrence at Montreal, which is
likewise tubular 1t is a mile and threequar-
ters long, and the single line of rail is 60 feet
above the river level. In the tubes there are
over 0OOO tons of iron; the surface to be paint
ed exceeds 30 acres, and the annual crop OF
| rust which has to be removed is very large.
tubular bridges are not cheap, and the cost
OF Their maintenance is great, so that no more
| OF them are likely to be built; but it was to
them we owe the first Introduction of wrought
| IRON IN long spans upon railways.
AT Niagara Falls is another of the worlds
great brdges-Roebling's railway suspension
Drldge, winch has span of S21 feet and
track 245 feet above the stream. With this
bridge very remarkable operation was per
formed about a couple of years ago. The
stone towers holding the huge supporting
cables-each cable has 3640 wires-werc dis,
lntegratlng owing to the rollers over which
the cables passed having become iammed so
as to prevent the cables moving freely over
them, and thus throwing additional strain on
to the masonry. To relieve the towers skele-
ton iron towers were built up round them
and the cables were transferred from the stone
to the iron by hydraulic arrangements with
out interrupting the traffic across the bridge.
The great suspension bridge between New
| \ ork and Brooklyn is one of the worlds woh-
ders., 1t was thirteen years building, and the
| length of the wire in the four cables, eXclli-
a central spar. Of nearly 1000, feet two land
spans each of $50 feet, and with its ap-
proaches is 59S9 feet long. The road is 135
feet above the water, the towers are 21S
| feet above high water and on them are hung
| four cables supporting two carriage-ways, two
| lines OF railway and an elevated footway,
which between them weigh nearly 1000 tons.
There is one danger in suspension bridges
When the weight is on one half of the bridge
the, other half rises, owing to the pull of the
cable, and any rhythmic motion has en-
dency to shake the roadway to pieces.
AT Angers, in 1SoO, suspension bridge
across it, and 226 were killed by the accident.
Had they 'broken step"-that is, walked ir-
regulary-this would not have occurred
China possesses the largest bridge in the
world. 1t is at Langang, over an arm of the
China Sea, and is five miles long, seventy feet
high, with roadway seventy feet WIDE ard
has 300 arches. The parapet is baustrade
and each of the pillars, which are seventy
five feet apart, supports a pedestal on which
is. placed a lion twenty-one feet long, made
| of one block of marble.
The highest bridge in the world is the rail-
way yiaduet at Garabic,, in France. 1t is
1900 feet long, and the height from the bed
of the river to the rail is 413 feet
The highest bridge in this country is the
Erie Railway bridge at Kinsua, near Brad
ford, Pa, which is 2052 feet long and 3O1
feet above the water.
The longest floating bridge in the world is
across the Hooghly at Calcutta, which is 1850
feet long.
A more usual style of bridge for navigable
streams is the Swing bridge or draw
bridge" of which there is an example in New
Jersey, allowing two free passages, each ZIG
| feet wide.
Of all the bridges of the world, London
Bridge is the most historic, but it is a rather
small affair for the present day. The centre
arch is l52 feet span, the two on each side
are of 140 feet span and the two others are
13O feet span, the width of the roadway be-
ing fftytwo feet.
Over the Dee, at Chester, England, there is
a stone bridge which has a stone arch 200
feet long-the longest in Europe; but this
country has one longer.
Over the Cabin John Creek, in Virginia, the
| arch 22O feet long, which is the largest stone
arch in the world.
Finally, come to the largest and in
some respects the greatest, bridge in the
world Qairly rivaling that over the Firth of
Forth the bridge over the Hudson River at
Poughkeepse, N. Y.
This bridge was built to form a link for the
New England railways with the Western
roads Prior to its completion all traffic from
make detour, either north or SOUTH to cross
the Hudson; the new bridge furnishes almost
an airline from Boston to Pittsburg.
The idea of building it was conceived Gftv
years ago, but it was not until the year 1868
that the idea took any definite shape. In 1872
plans were drawn and a charter secured but
the panic of 1873 stopped progress. In 1874,
however, new organization was formed. and
in August, 1876 the first borings were made
in the river bottom.
From that time the work proceeded until
the bridge was completed, in 1885, On the
18th OF August, of that year. the last min was
driven into the cantilever span, and the great