The Ottawa free trader. [volume] (Ottawa, Ill.) 1843-1916, 1885-04-04
From New Orleans.
NEW ORLEANS, March 20, 1885.

NEW ORLEANS, March 20, 1855.
In former letter on the Mexican depart
ment Justice was not done to the exhibit in
natural history, literature and art, nor to the
beautiful marbles and onyxes, the interest
ing exhibit of sugars, or the very large dis.
play Of native liquors.
Within the past week two very great at
fractions have been added to the already
large and interesting exhibit Of Mexico.
One is the opening of the Mineral Build
ing, beautiful structure in the Moresque
style, gorgeous with stained glass windows
and dome, and brilliant painting In the
richest of colors. e.t.
Within this building, as fit setting for
the rich treasures of her mines, Mexico
displays samples Of all the ores that bring
her wealth, gathered from every state OF
the republic. "a III Ia ~ 3 .
To certain extent, however, the very
magnifcence of the display defeats itself,
for seen in the flood of colored light pour
ed from the brilliant-lined windows and
dome, the minerals lose almost all distinc-
tiveness and their naturally beautiful colors
are obliterated or entirely changed.
The other exhibit is that ORA working
model of the Tehnahtepec Ship Railway
system, projected by Captain James b.
Eads. The mode, which is finely finished
and is said to have cost SIC, 900, Sis 83 feet
long and consists of portion of the basin
leading from the harbor, the lifting pom
toon, section Of the railroad track, with
ship carriage and turntable.
A ship seven feet long and weighing $50
pounds is used, and the operation of rails
ing the ship from the water, transporting
il on the railroad, turning it on the turn.
table and returning 1t to the water, Is gone
through with many times a day to large
and appreciative audiences. fl st
As this railroad seems to be destined to
be built and used, a brief description of
the working of the system may be of inter
est. To make It clearer the working di-
mansions of the railroad will DO given.
A pontoon or floating dock, IS feet deep,
IS feet wide and somewhat longer than the
longest vessel to be transported, is arranged
with water-tight compartments, so that it
NAV be made to sink or float in basin of
water by pumping water into Or from these
compartments.
On this pontoon, running on rails cores
ponding with those of the railway, is a
cradle capable of supporting and carrying
loaded ship.
The pontoon with the ship carriage on it
10 sunk, by admitting water into its com
partments, to a depth sufficient to allow the
ship to float over it. The pontoon is then
pumped out until its deck is on level
with the railroad track. Engines are then
attached to the carriage and the ship Is
hauled off on the railroad track, to begin
its journey across the isthmus. A reversal
of this process transfers the ship to the
water again.
The track has six rails the outer ones
being 90 feet apart. On 1t runs the ship
carriage, consisting of strong transverse
Orders, supported by 800 wheels, each one
double Hanged and having an Independent
axle. Between the Orders and each wheel
is strong spring, which will not be fully
closed by the weight of the heaviest ship.
To support the weight of the ship without
unequal strain, 1870 supports are used, re-
sembling somewhat In appearance the or
binary orchestra music stand. These sup
ports consist OF strong steel columns, bear
ing at the top by means of teggle joint u
plate about three feet square. These plates
will be cushioned to prevent injury to the
ship The columns may be moved freely
up and down, but are capable of being
locked firmly at any point by means of a
strong screw nut When the ship is run
on the pontoon a series of connected ny
draulic rams raise these columns SO that
the plates bear firmly against the sides and
bottom of the ship. The valves admitting
water to these rams are now closed and the
ship raised by pumping the water from the
compartments of the pontoon. z--a--.
The ship now rests upon the $50 steel
columns, which In turn are upheld by as
many columns of water in the hydraulic
rams. As these rams are all connected, 1t
is evident that each support bears Its exact
proportion of the weight Of the ship. The
screw nuts are now turned down, locking
the columns firmly, and the rams with
drawn, transferring the weight to the car