THE CHINA MAIL.
SATURDAY, OCTOBER 18,
The WORLD'S GREATEST DAM
THE CAN UNDER CONSTRUCTION
IZBELOH
Structure Stretching Across the Tennessee
River Exceeds All Others in Size--Will Generate Vast Volume of Electricity.
(By MALCOLM MacDONALD.)
Score another mummoth construction achievement for the United States Government, in the building of the "Wson Dam across the Tennessee
The future of the enterprise may be involved in question, but the fact remains that the dam is the greatest masanary structure in the world for the impounding water. There is no exception-not even in the case of the famous dam on the Nile at Abpuan. The Wilson dan sota a now record for the amount of masonry required in hydraulic development:
Some idea of the size of the project may be gleaned from the statement of dimensiona, The total length of the structures spanning the Tennessee is approximately forty-five hundred feet, or practically seven-eighths of a mile. Even for a bridge this would represent an ambitious undertaking. For a dam it is stupendous.
accompanying A glance at the illustrations will carry out the impres- xion of size better than figures. With the striking emphasia they show enormous dimensions of the structure which has been the subject of so much controversy in connection with the Muscle Shoals problem confronted by Congress.
Like A Nine Story Building. From river bed to crest the dam has a height of ninety-five feet-almost
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equivalent to that of a nine story office building. This, of itself, proclaims the magnitude of the undertaking, but it is by no means the whole story. For a structure of such size it is necessary toś go to considerable depth below the normal bed of the river, in the con- struction of massive foundations. By including foundations and the operating bridge which forms the top of the dam we add almost four stories to the build. ing with which the dam is under" comparison. This brings the structure to a height approaching that of a building of thirteen stories, or a tota! of 346 feet.
In massivoncer of bulk
the Wilson dam stands alone, This solid structure is 105 feet thick at the base and stretches across the river for a
distance of considerably more than half a mile-3.050 feet, to be exact. The mind refuses to grasp the volume of
solid masonry required in a structure 'The of these enormous proportions. inclusion of the immense power house, makes the figures all the more out of
grasp. The power house forms a part of the dam and increases the length by Simple the addition of 1,250 feet.
addition, shows this to give a total length of 4,800 feet, or more than elght-tenths of a mile. The remainder of the length is furnished by the 200 foot lock, extending from the north end of the dam proper to the northern shore of the river.
ر عمر شما از بین مومن
Equivalent To A Mighty Wall,
In terms of plain English the masonry in the entire project is of a volume that would build a wall more than seventy-five hundred miles in length a yard thick and a yard high. Starting at New York this wall would stretch across the continent by way of Chicago to Portland down to Las Angeles and buck to, New York over a southern route which would cause it to
enclose a goodly share of the whole United States. In more figures the masonry amounts to 1,850,000 cubic. yards.
In the construction of this mammuth dam the United States Government was confronted by the problem of giving water-power development without inter ference with navigation
the Tennisлee River.. To accomplish this Lit was necessary to provide locks, for lifting or lowering steamers and other
от
WILL
craft between the level of the water below the dam and the high level of the
giant. upper waters created by the structure. There are two of these. locks, each of them affording a lift of forty-six and one-half feet, or ninety- three feet for the two. This part of the undertaking represents a good deal of an engineering feat within itself. To lift vessel to the height of an eight or nind story building is_nor mean
The enterprise.
two lucka, one immed lately above the other, accom plish this in comparatively short time. The capacity of the locks is indicated by a length of 300 feet and width of 60 feet for each of them.
·
Held By. Own Weight, The dam. is of the gravity types. structure doponding primarily upon its own weight for ability to resist over- turning or sliding on its base. This class of dam has been in successful use
A GLIMPSE OFF THE LOCK UNDER Co
SonG THE EXCAVA
three times na much watarina, passes down the mighty St. Lawrence river between the United States and Canada. Simple Control Of Flood Gates. Not the least impressivo feature of the great dam is the manner in which the flood gates are controlled. The system is so complete as to mechanical operation, and no simple as to manage- ment that one man will be able to open: or close all of the gates within a period of two hour.
When man builds u dam of this kind the creation of a vast artificial lako in an inevitable consequence. The water': held in check must find accommodations somewhere and the higher the dam the mare extensive will be the backing up pl'ocess, In the case of the Wilson dam the body of water thus established сотега A counterable expanse of territory. The dam will exert its influence up-stream for a distance of eighteen miles. In places this 18-mila. lake will spread out to considerable width. The average distance from
here to shore will be approximately three-quarters of a milo.
For
In an enterprise of this kind the engineers can tell before a stroke of work in attempted the amount of power that will be generated by the impound- ing of the stream. They know the extent of the fall, the volume of water passing through the channel and the force exerted by this current in its descent. With the Wilson dam project. it was determined that the flow would operate power units of 600,000 horse power, which is to be converted into electricity on a atupendous scale. Kilowatts and almilar figures terrify me, but when the army engineora talk to me in terms of fuel saving I can grasp their meaning. For this reason I am impressed with the magnitude of the undertaking when they tell me that the electric current means a saving of nearly ten thousand tons of ecal every day in the year.
Ten thousand tons of coal a day! The figures are startling, and they are easily brought home. For this purpose. I let myself imagine a town of a thou- Band homes-five thousand people. With each family using ten tons of coul year the total requirements of this town would be ton thousand tona. At Afty tons to a car it would require train of two hundred coal cars to hatil this fuel from the mines to the coal yards.
ton the At twelve dollars a conl bill would be $120,000 for this community.
Is it any wonder the United States Government went into the project as a war enterprise and concluded to push it to completion in times of peace? The cost is given by the army engineors as more than fifty million dollars. This seems like a lot of money, but it is less than fifty cents to each person in conservation project the dam is worth the country. As an engineering and
the, money.
for centuries without the discovery "of trouble with-flood waters. In arrang-
Engineers declare a better design.
Ing the overflow of the dam the that it is the most dependable type engineers took every precaution to where the aim is to provide perman- make sure that high water should not ence, heavy duty and low cost of overtax, the capacity of the spillways. maintenance. Reinforced concrete con- For the normal stage of the current struation, using steel roda, has been there are thirteen special openings, applied only in such parts of the job equipped with butterfly valves."
The work has been carried on entirely as made it possible for the exterior flood periods there are 58 flood control by day labour, under the direction of surfaces immediately adjacent to be gates, stretched along the greater kept waterproof throughout all con- portion of the length of the dam.
engineer officers of the United States Each Army. The construction work was ditions of actual operation. This pre-of these gates has a height of 18 feet started early in 1018. With two
and a width of 38 feet. These open-interruptions it venta the deterioration of reinforcement
pushed ings will take care of tremendous flow continuously. Barring unexpected dif- of water, equivalent to a discharge officulties the project should be ready for almost a million fest every second, or, commercial operation in October, 1925.
which would occur where waterproofing could not be perfected and maintained. No chance has been taken on future
has 'been
Possibilities of the Snap- per Under Domestication -Soft-Shell Turtles a Great Delicacy-Uncle Sam's Preserve for Green Turtles Breeding the Terrapin.
(By RENE BACHE)
Why not develop a turtle-framing industry, to help out the diminishing ment supply, 'and to give tho' American family something really worth while and delicious in the way of food?
The Government Fisheries Burcau earnestly advocates the idea. There is for instance the snapping turtle, native to streams, lakes, and ponda all over this country, as far went as the Rocky Mountains. They could be bred in practically unlimited numbers by method substantially the same as that now used successfully, though on a small scalo, by the Fisheries Bureau for propagating terrapin.
Half the weight of a snapping turtle is clear meat, which makes outlets, stews, and curries. Tho liver and eggs help to enrich the much-esteemed snap- per soup, and the shell in an excellent substitute for a soup-bone.
In the Gulf States these turtles grow to giant size. The so-called "alligator snapper," vory abundant in the swamp of Louisiana,, seraetimes weigh as much as 200 pounds.
The Snapper.
In Japan the snapping turtle as a delicacy is esteemed as highly as we regard the terrapin. There are in the near neighbourhood of Tokyo a dezon turtle farms, which ́yiild an annual crop of three-quartom of a million snappers. It is a very profitable industry.
In our own country the snapping turtle is highly esteemed as a delicacy
TURTLE FARMS
AS A SOURCE OF MEAT SUPPLY
AGAY "ALLIGATOR.
answer is that if they once came to makes perfectly good and palatable be properly appreciated as food, they food, and, when prepared by a skilled would soon go the way of the terrapin. I cook, in distinguishable from the much- On the other hand, snupper farming esteemed and expensive diamond-back would develop a new, valuable, profit-only by a laste educated in' auch, abla, and permanent source of food matters. supply, if the requisito demand could be crasked, in this country, as it always exista in Japan.
Turtles With Soft Shells.
THEIR LOGS
YO WA YOUNYC
Ott
TERAAPIN
par THE
Mud turtles are always cheap and plentiful; they can be bought in the market for a few cents'aplece, and find randy unle to restaurant-keepers. In The Fisheries Bureau paints out that | summer they crowd, together, in- great in the apper Mississippi Valley and in numbere, In ponda and sluggish many Borthern lakes' there are species streama, and are easily taken in traps. of soft-shelled turtles which for eating (A simple device for the purpose is a purposes are hardly inferior to the log that projects out of the water. All *** by epicures, and in Loulalana the hunt- diamond-back terrapin. For soups, around, save at the submerged end, Ving of the huge alligator snapper stews, and fried cutlets they are a net is placed. The turtles drawi ont which owes its name merely to its sizedalicious. In towna along the on it tà aun themselves, and, one after and swamp-dwelling habit--is a rather | Mississippi and Illinois Rivers they are another are pushed of the end of the important industry. Shapper soup and consumed in large quantities; but con- log by those coming from behind, into devoid of vegetation and so low as to farming which has now gone far enough snappers. But terrapin are native to should be put back into the bed, leaf snapper stow are favourite dishes in ramption of them is local, and they are the net. New Orleans restaurante. But there not shipped to distant markets.
Monster Sea Turtles.
be wave-swept during every gale. This to enable the experts to recommend it I salt or brackish water, and the ponds they freeze. As in the case of the Lis in the United States no widespread. In the summer time these turtles The green turtle has, long been the Breton Leland Reservation, which as a practicable. and worth was ramst he so located and constructed as snappers, and for the same reason, the
popular acquaintance with the reptile assemble on sand bars and the banks of regarded a first-clas
was set aside by Executiva proclama-business. himary
to be averflowed at high tide. Ideal Hittle ones as an article of food. Thus, while the stream. They are exceedingly timid, especially for its incomparable soup, erataver
tion In 2004 a "refuge" for wild
are kept apart from the The requisite plant is inexpensive. conditione are afforded by a swampy adulta. terrapin have been well-nigh, extor and ai the slightest alarm shuffle of and for that very reason it has been
Once fairly started, a terrapin farmer ared in which all but the egg bed is As soon as the egg-laying sersón 'minated to supply the market, snappers with surprising agility into the water, hunted merclissaly, as to threaten The green turtle, when foll-grown, should be able to hatch 16,000 ears per❘ covered by water at high tide, but from over, the egg bed is shut off from the are still fairly plentiful, and acquisi. Fresh caught, they do not ship well the species with extermination. For weight 900 for occasionally 1,000 year. In the afth year after hatching which at low tide the water does not rest of the breading pond, so that the tion of breading stock for farining them which has something to do with the merly very numerous along the Florida pounds. It lives in deep water and is allowing for a mortality of 25 per wholly retreat. This gives the turtlesers may not be disturbed, and marsh In this Japanese manner would be sang fact that so littld is known about these coast. It has forsaken those waters for strictly vegetarian, feeding on marine cont, which is well over the mark), at an opportunity to crawl about and ann grass
MARINERA AS (spodden, autside" the regions to which; ] the 'nhores of Yucatan, transferring its | planta. Iti, favourite provender is '|'least,' 8,000 will have reached a 5-inch themselves.' DIETY bed f; af cold weather, the terrapin become**
about protective growth.
is allowed to cover it within
At the beginning! Hepping turtles mud, up during they the nativeBut in cold atdrage or breeding grounds clear across the Gulf kind of son-wood known to fabermen length. That is 600 doren which, if At one end of each pond a the gold months in berry, places, under in refrigerator cars they can be handled of Mexico.
na “iturile, iratrilon," bebich it "cuts; or they fetch only $20 a dozen, represent sand is built to the height of 4 foot sluggish, and finally barrow into the Torworbitinin munkrat holes to exodent advantageukia Within" recent years, the Federal Gear the ropte, eating only the lower a selling value of $10,000. Six-Inch | above high tide leval-sloping, so that, hand or mud of the bottona, remaining- Occasionally; dozens of thann Swill, bef 5 Nowadays terrapin stew is commonly government has established what might parts, so that the tope are left floating. terrapir kring denble ikat, price, but to the females can crawl up and dig holes | buried until the warm days of spring found in single mulrat" "horrow on the bills-of-fare of restaurants and be called a green turtle Tarmonise latter, collecting in large folds, add the extra inch requires two or for their egg Hatched in August, the arrivano Thy, and exceedingly voracious, food hotels 40 35 a portion. That it double scale, which la gilding most gratifying Motify the turtle-hunters of the where three additional years of growth. young do not emarge, from the bed. In former deysi terrapin werd vastly Eng on, frogs;... fishta, (crawkab, and, the pre-war price. But what the ton reuita. It, iron or about 500 poate of their prayers, an
“ Breeding" The Diamond Back... ordinarily until the following, spring, labundant in the Delaware and Cowan dienstimes young: birdá, 0)
gets 'Xis fanally ⠀⠀ noi | square miles on the months of Abe fror arumral yuara past the Fisheries! In their mala cosentielt, the mathods though a few, may be found terawling peaks Bays and in the sounds of North at af, but "alider that is to map Elvanka wild a region Bureau has been conducti at Bena- developed by las experts are much like | about in hautumn, it sharo be a warm | Carolina, commonly toning it dve cas ary imp turtle. The latter
chadaland Krisdy lalanda's the
fort ON.CZ:
those need in Japan Zow tku brendingát, spall......... Buch "adventurous specimens t
timight be asked, linajoping thirties-- ter
plastiful, why brend them) "UTEC.
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