The farmer and mechanic. [volume] (Raleigh, N.C.) 18??-19??, 1907-10-01

would form a soiid train Of that width
encfrciing the giobe at the equator.
The weight Is indeed ~stuDendous
and the force nconcsivable Never
theless. during the floods fully as
much water runs through the dam
every day az the whole supply kept
back in the dry season and the struc-
ture had TO be uade SO that II would
retain this huge lake and Al Hood
time let a lake equal To IL pass
through every day.
Grcat Than the Pyramids.
Talk about the Pyramids, The As
souan dam ~ far more wonderful
than they. The Pyramid OF Cheops
required 100. 900 men and thirty years
IN its building. The As=ouau dam
was constructed by about IL. 600 men
in four years. The Pyramid was
fshed the people. The dam cost al
together about $4,000 900. and h
men who WORKED upon il were better
paid than any others who have ever
labored in the valley or the Nile.
Moreover, the dam has made Egypt
the most prosperous country OF the
world. II has added TO IT more than
100000 acres of tillable land and
has increased its crops a value OF
more than s13, 900 900 per anpum 1t
has more than paid for It's cost every
year. Since II has feen quilt the
yearly taxes have increased $1,000
600. and the lands owned by the gov
eminent nave become worth s. $780,
900 more. BY the raising Of the dam,
as now planned. there will be an
enormous additional increase. The
scheme decided upon il to raise the
dam fifteen feet. This will almost
doubl the amount of water stored
and double the benefit to Egypt.
\ Wonder OF Mechanics.
The Assouan dam is more wonder
full than the Ply. amids in its mechan-
ical construction. Old Cheops is built
On the edge of the desert on asoIid
stone platform, IN It is little more
than the piling Of one stone upon
another. For the Assouan dam a
trench a hundred feet wide and a
hundred feet deep had tn be exca-
waited in the granite rock; it had TO
he bedded with concreted rubble, and
il was upon such a s~ubstructure that
the masonry was raised. The dam
itself contains more han a million
ton of granite and about Is, 900 tons
of steel, and the calculations of the
engineers are such that hey know
just now much water every ounce of
stone and steel will hold back. They
know the exact weight of the river at
every hour of the day, and they have
Geographic reports which tell them
what the Nile is doing in Abyssinia,
in Central Africa and the Soudan.
They have dispatches as to every
great rain, and they know to n ton
just how much water Lower Egypt
is using, so that they can tell how
much or how little to let out for the
farms. They even estimate the force
OF the sun on the water and know
how much it drinks up every day.
When the reservoir is full Old Sol
takes a million and a half tons from
1T every tWenty-four hours, and the
engineers estimate the evaporation
not only at Assouan, but all along the
great stream and throughout its
sWamps to its source in Victoria lake.
/ have had some talks here with Mr..
Mcdonald, the engineer-in-chief of
the dam. and am surprised at the
wonderful intelligence bureau which
Egypt possesses.
What a Child a Do.
I am also amazed at the strength
and ~delicacy of the machinery of this
remarkable structure.
1t is SO arranged that q child can
operate it. The great sluice gates are
each as high as a two-story house. and
so wide that you could drive a hay
wagon through them without touching
the walls. They are cut right through
the granite dam and are closed or
opened by steel doors, which move up
and down inside the wall on rollers.
Upon the top of the dam there are
machines for moving these gates, and
they are so made that a child could
operate them. They are SO equipped
that they can be moved by electricity,
but they are now worked by hand,
and this mighty force, SO great that
1000, 600. 900 horses would be re-
quired to move it, is now controlled
at will by the muscular power of a
single man.
This thought was impressive as |
sat below the dam. right where the
eight central s1uiceS pressed onward
by the millions of tons of water lying
behind them pour forth their mighty
flood. / had climbed down the steps
at the north side of the center of the
great structure to make a photograph
of the streams flowing through.
They come forth with a rush as great
as that of Niagara and go ~foanling
over the rocks with a force that
might generate thousands of horse
power. The noise is like thunder and
the streams fairly shake the earth
Each is about fifteen feet in height
and is as yellow as mud. There were
eight such streams of gOlden foam at
nv right, and further over | could
see the spray from others all dashinS
through the dam until they met in a
yellow toaming mass several hundred!
feet below me and rolled onward
down the rocks to Egypt. he flow
out with such force that they tear
up the rocky bed of the Nile, lifting
stones weighing many tons and car
rying them some distance down the
stream. They AVE done 50 much
damage of his nature that a cement
foundation has now been made below
the dam itself in order to prevent the
eouging out of the bed and thus UNI
dermining the main structure.
FRANK G.. CARPENTER
Sargent S. Prentiss
UInriU9Upd GpniuS