xt7h445hbc5h https://exploreuk.uky.edu/dips/xt7h445hbc5h/data/mets.xml Haupt, Herman, 1817-1905. 1855  books b92-143-29441776 English T.K. and P.G. Collins, : Philadelphia : Contact the Special Collections Research Center for information regarding rights and use of this collection. Ohio River. Consideration of the plans proposed for the improvement of the Ohio River  / by Herman Haupt. text Consideration of the plans proposed for the improvement of the Ohio River  / by Herman Haupt. 1855 2002 true xt7h445hbc5h section xt7h445hbc5h 




A



     CONSIDERATION OF THE PLANS




             rP.OPOSED FOrI TUE




IMPROVEMENT OF THE OHIO RIVER.





                 BY

        HERrMAN HAUPT,
             CIVIL ENGINEER.



         P1H I LADE L PHI A:
T. K. AND P. G. COLLINS, PRINTERS.
              1855.

 This page in the original text is blank.


 







THE



    IMPROVEMENT OF THE OHIO RIVER.



  THE elaborate treatise of Charles Ellett, Jr., on the
improvement of the Ohio and Mississippi Rivers,
and the preventive of inundations, has probably
been read by few without a feeling of obligation to
this gentleman for the exceedingly valuable con-
tribution to practical science which he has given to
the world. He has undertaken the solution of one
of the most grand and important problems that
could occupy the human mind. He has grappled
with the difficulties which it presented, and has
apparently proved with the clearness of demonstra-
tion that it is possible for man, limited as his physical
powers are, to say to the father of waters, thus far
shalt thou go, but no farther, and here shall the
mighty volume of thy turbid waves be stayed. He
has attempted to show that the region of the Lower
Mississippi may be protected against inundation,
that the freshets which annually cause immense
destruction to life and property, and the effects of
which, by a continuation of the present order of
things, must become more mischievous from year to

 



4



year, are perfectly controllable, and that too with
an expenditure of capital which, in comparison with
the advantages to result from it, would be abso-
lutely insignificant.
   The surface of high water in the Lower Missis-
sippi is nearly twenty feet above the surface of the
country at points several miles distant; the sole
protection against overflow is by means of slight
banks, called levees, raised upon the sides of the
stream. These embankments are in constant danger
of destruction from the pressure of water in high
floods, causing breaks or crevasses, which are annu-
ally becoming more disastrous in their effects.
  In proportion as the upper portions of the great
basin of the Mississippi become peopled, and the
forests recede before the axe of the settler, the
drainage becomes more rapid and the volume of
water discharged in a given period is increased;
other causes are also in operation which accelerate
the discharge from the Upper Mississippi, and hasten
the inevitable fate of the doomed regions of the
delta, unless timely aid from artificial means shall
be afforded.
  No improvement should be considered more truly
national in its character than that which would
afford protection to this garden spot of the Western
Hemisphere. It is the extension of the boundaries
of freedom; it is the sale and settlement of the public
lands in the new States and Territories, and the re-
clamation of swamps by the construction of new
levees along the tributaries of the Mississippi. It is

 



5



to the operation of all these causes that the danger
to life and property in the delta can be traced.
But these operations are indispensable to the pros-
perity of the nation, and imperatively demanded by
that irresistible spirit of American progress, which
is even less controllable than the waters of the Mis-
sissippi. It is unfortunate that the extension of
improvements, of arts and civilization, cannot be
secured without attendant evils; but these evils can
be mitigated if the people of the West, who are the
recipients of the benefits, will permit a very small
expenditure from the national treasury to compen-
sate for the disturbance in the primitive condition
of things, which their agency has produced. Mr.
Ellett believes that a small appropriation by the
general government will be sufficient to check the
ravages of flood, to control and regulate the dis-
charges of the Mississippi, to reclaim thousands of
acres of the richest lands now subject to inundation,
and relieve the river plantations from the increas-
ing expenditures required in the annual extension
of their levees. All portions of the Union are in-
terested in securing objects so national in their cha-
racter, particularly when other advantages resulting
from the means to be employed are taken into con-
sideration.
  The most important of these incidental advan-
tages, and that to which it is proposed to direct
attention in the following pages, is the improvement
of the tributaries of the Mississippi, and the com-

 


6



mencement of a plan of artificial inland navigation
more extensive than the world has ever yet wit-
nessed; more beneficial in its influences upon national
prosperity than any other of which it is possible to
conceive; and more economical in first cost, and in
subsequent expenditure, than any other means of
inland communication.
  Mr. Ellett has considered this subject in connec-
tion with the regulation of the floods, and has shown
from an accurate record of observations, extended
over a period of six years, that the fall of water
upon the surface drained by the Ohio is sufficient,
exclusive of loss by evaporation, to maintain a
regular current of sufficient depth for navigation
throughout the year, and a similar condition of
things would no doubt exist upon nearly all the
other great tributaries of the Mississippi.
  The plan proposed by Mr. Ellett for accomplish-
ing the double purpose of preventing the possibility
of inundation, and, at the same time, of furnishing
a constant depth of water for navigation, consists
of the construction of immense reservoirs, forming
lakes in the mountainous regions in which the
sources of these streams are found. He has shown
that the average annual discharge of the Ohio
River, from observations at the Wheeling bar, is
835,323,000,000 cubic feet, sufficient to maintain
the river at a uniform height of 8.P4j feet during
the entire year, but that the quantity which it is
necessary to retain to prevent the injurious conse-

 



7



quences of the highest floods, is only 44,190,000,000
cubic feet, a volume equal to the discharge of the
river during a five feet stage in fifty days. A sin-
gle reservoir four miles square, and about one hun-
dred feet deep, would be sufficient for this object, or
an equivalent number of smaller ones.
  It is by such calculations that Mr. Ellett demon-
strates the feasibility of his reservoir plan, and
proves very clearly that, if locations can be found,
it is competent to prevent the injurious effects of
floods, while it secures at the same time the equally
beneficial result of maintaining a constant depth of
water sufficient for navigation by vessels of moderate
draught.
  That some modification of the reservoir plan, or
some addition to it, is the proper one for securing
the objects sought, there can be but little doubt; but
there is room for diversity of opinion on the question
of the location of these reservoirs, whether in the
mountainous regions at the sources of the streams,
or in the beds of the streams themselves, by the
formation of successive pools along their channels.
The relative advantages and disadvantages of these
two modes of construction will be discussed here-
after.
  The subject of the improvement of the Ohio is
no new idea; it has long engaged the attention of
the highest intellects in the United States. The
consequences of low water, suspended navigation,
fluctuation of rates, stagnation in the stream of in-

 



8



land commerce, and other attendant evils, were too
serious to escape the observation of public spirited
individuals who labored in devising plans to over-
come the difficulties, but these plans, in general,
sought only to palliate the evil, not to eradicate the
disease; they were mere temporary expedients, in
most instances applied for local relief, not general in
their character, or sufficiently comprehensive to em-
brace all the defects of the existing systems and
satisfy the just claims of the community.
  Some years since, a large national convention met
on the western waters, which gave the subject of
improvement by slackwater a favorable considera-
tion. The lamented and gifted statesman, John C.
Calhoun, was President of this Convention, the
members of which represented the highest talent in
the nation, but the deliberations of this body were
not followed by action. Prompt energetic action,
even if sometimes hasty or misdirected, is more bene-
ficial in its results than that timid caution which
hesitates to act for fear that it might not act pre-
cisely right; delays are often fatal, and if an im-
provement of the Ohio is ever to be effected, it will
be the result of a commencement made by indivi-
duals actuated by considerations of public good
rather than by the stimulus of interest. The im-
provement never will be commenced if that com-
mencement is dependent upon the action of Congress,
and is delayed until members have expended their
verbal ammunition upon the subject.

 



9



  If it be considered important to control and regu-
late the discharges of the rivers of the country,
confining their fluctuations within prescribed limits,
preventing the devastations of floods, and providing
a permanent supply of water for the purposes of
navigation; if commerce between the distant States
of our vast Republic is an object deserving of en-
couragement; if low rates of transportation and
facilities for effecting exchanges tend to the develop-
ment of natural resources, and to the increase of
wealth-then must the improvement of our great
rivers be regarded as an object of national import-
ance, in view of which sectional interests and local
prejudices should be laid aside, and the representa-
tives of the nation unite in a plan for efficient and
immediate action.
  Although the citizens of Pittsburg and the inha-
bitants of the State of Pennsylvania may reap a
more abundant harvest from the improvement of
the Ohio than other portions of the Union, yet it is
difficult to conceive of any improvement, the bene-
ficial influences of which would be more generally
diffused throughout the extent of our land. Pitts-
burg, it is true, would become the head of the most
extended inland navigation in the world, but Phila-
delphia would not monopolize all the advantages of
a connection with it. By means of the Alleghany
Valley Railroad, New York would tap this trade
with a six feet gauge connecting with the Erie Rail-
road, while a still shorter line to New York would

 



10



soon be completed through the Sunbury and Erie
Railroad, the improvement of the Ohio would carry
with it, as a necessary consequence, the completion
of the Alleghany Valley Railroad connecting with
the New York and Erie Railroad, and the Sunbury
and Erie, which, with the Catawissa and other roads,
would form the shortest and best line of communi-
cation between the city of New York and the Great
West.
  The New England States and cities would com-
municate with this great channel of trade by means
of the same improvements, and an immense amount
of eastern capital and influence would thus become
directly interested in the early completion of these
Pennsylvania railroads.
  Maryland, by means of her Baltimore and Ohio
and Northwestern railroads, would tap the trade of
the Ohio before it reached Pittsburg. And possessing
so great an advantage over all competitors, Mary-
land and Virginia can, of course, be relied upon to
give the proposed improvement not only an ap-
proving smile but a liberal appropriation of mate-
rial aid.
  Ohio will be directly benefited in various ways:
In the facilities afforded for obtaining a regular sup-
ply of fuel from the great bituminous coal fields of
Virginia and Pennsylvania, and at fixed and mode-
rate rates; in the transportation at extreme low
rates of live stock and all kinds of agricultural pro-
ducts; and in the increased value which these facili-

 



11



ties will confer upon the lands in the State. Even
the Ohio railroads, which, at first view, might be
supposed to suffer injury from a loss of a portion of
their heavy freights, will, in fact, be gainers from
the increased travel and the exchange of commo-
dities requiring rapid movement, to which facilities
for the cheap transportation of heavy freights give
rise.
  The experience of New York has shown that her
canals and railroads, instead of being antagonistic,
mutually assist in sustaining each other, and the
facilities afforded by one increase the business of the
others. So it must be with the improvement of the
Ohio; the shippers of coal and other heavy freights
will travel by railroad to anticipate the arrival of
their property, and having effected sales, will seek
the same channel of conveyance to return.
  Time is money, and the value of time is so fully
understood and appreciated, that no tax imposed
upon travellers within reasonable limits will drive
them from the railroad; the greater the extent to
which business can be increased upon the river, the
greater will be the travel upon the railroads of Ohio.
  The same remarks are applicable to Indiana and
other States west and south of Ohio; and these, with
the new States and Territories in the Northwest, are
bound, by a solemn duty to their fellow-citizens, to
aid, if possible, in retarding the progress of that de-
structive element, the effects of which are increased
by their improvements. If the reservoir plan is

 



12



practicable, and the floods of the Ohio can be re-
tained, it is evident that the increased drainage of
the other tributaries of the Mississippi will not, for
a long period, increase the heights of the floods in the
lower part of the valley beyond the present limits.
  To the inhabitants of Louisiana, Mississippi, and
Arkansas, the improvement under consideration
should be a boon of inestimable value. The success
of the Ohio improvement would establish a prece-
dent, soon to be followed by similar operations upon
the Upper Mississippi, the Missouri, and their tribu-
taries, diffusing the benefits of commercial facilities
to the most distant portions of our territory, but,
what is of more value to them, holding the waters
in artificial lakes until the wants of man required
their discharge, and by these means so regulating the
flow of the streams, that crevasses and inundations
would be known only by the records of history.
  The evils and defects of the present navigation
are universally admitted; during the present season,
a continual suspension existed for the period of six
months, during a portion of which the exposed
channel of the Ohio exhaled death-dealing malaria,
adding the calamities of a fatal epidemic to the dis-
tresses of suspended business and financial embar-
rassment.
  Government has in vain attempted to cure the
evil; the remedy has, it would seem, in some in-
stances, been as bad as the disease; the wing-dam
system could, at best, add but a few weeks to the

 



13



period of navigation; it has no power to control the
floods, or retain the surplus to supply deficiencies.
  The wants of the country require a permanent
navigation, free from the injurious fluctuations with
which it is now visited, a depth of water sufficient
to float the largest steamers of the Mississippi, and
to carry them at all seasons. This much the public
interest demands, and with less than this the public
will not be satisfied.

                    RESERVOIRS.

  The plan proposed by Mr. Ellett consists, as pre-
viously stated, in the construction of immense reser-
voirs upon the Alleghany and other tributaries of
the Ohio.
  The feasibility of the plan is discussed with the
ability for which the writer is distinguished, and
there can be no doubt that if suitable locations for
the reservoirs can be formed, sufficient water may be
retained to make a decided impression upon the
heights of floods, and retain a moderate depth of
water in dry seasons for navigation by ordinary
steamers; but there may be doubts whether reser-
voirs can be formed of sufficient capacity, and pro-
perly located, to contain the immense volume re-
quired to maintain a sufficient depth of water in
the channel at all times for boats of the largest class;
and if formed, it may also admit of doubt whether
the dams required in the construction of these reser-

 



14



voIrs in the mountains would be less expensive than
the reservoirs in the valleys, formed by the succes-
sive pools of an ordinary slackwater. It is certain
that a given depth of water can be maintained with
less waste by the construction of a slackwater than
in any other way. During a period of low water, the
only loss will be that due to lockage, leakage, and
evaporation, which would be but a small portion of
the discharge of the whole stream in a boating
stage. The reservoir plan may answer, and Mr.
Ellett seems to have demonstrated his positions, but
the slackwater will answer beyond peradventure;
and no experiment is required to decide the question
if the object is merely to improve the navigation.
  One of the most important objects which it was
purposed to secure by the construction of the moun-
tain reservoirs, was the retention of a sufficient
quantity of water to reduce the heights of the floods,
and prevent the destructive effects of inundations.
  Upon this subject, Mr. Ellett has furnished ex-
ceedingly valuable data-some of which are here
stated.
  During a period of six years, from 1843 to 1848
inclusive:-
                                     Cubic feet.
The maximum discharge of the
  Ohio at Wheeling, was, in 1847 1,142,258,000,000
The minimum discharge was in
  1845   .    .    .    .    .   555,482,000,000
The annual average .     .    .  835,323,000,000

 


15



  Which was sufficient to have maintained the river
at a uniform height of 8-1f feet.
  The minimum discharge in 1845 would have
been sufficient to maintain a depth throughout the
year of seven feet.
                                            Inches.
The annual drainage for the same period,
  averaged     .     .    .    .    .     . 14-
The maximum, in 1847      .    .     .    . 2042
The minimum, in 1845      .    .     .    .    -l
The average annual fall of rain at the head
  of the Ohio, is    .    .    .    .     . 36
  "The discharge is, therefore, about 40 per cent.
of the total fall, showing that 60 per cent. of all
the rain and snow that come to the earth in this
latitude is carried back to the clouds in vapor, and
never reaches the ocean."
  The writer also states that a great flood in the
Upper Ohio rarely continues at its extreme height
more than ten or twelve hours, and but a single in-
stance can be found, in the record of eleven years,
in which a rise exceeding twenty-five feet continued
longer than four days. When the river attains its
maximum height at any point, it is rising one hun-
dred miles below and falling one hundred miles
above, the velocity of the highest floods being sixty-
one miles in twenty-four hours.
  To protect the country from inundations, it has
been stated by Mr. Ellett, that it is only necessary
to retain the top of the wave, and as a flood of

 


16



twenty-five feet is found, by experience, to be pro-
ductive of no injurious results, efficient protection
will be secured by holding back the discharge in
any given time exceeding that of a twenty-five feet
stage.
  Taking the flood of 1841 as a practical example,
the total discharge of nine days, from March 24 to
April 1, inclusive, was 158,964,000,000 cubic feet.
  The discharge for nine days, in a twenty-five feet
stage, would have been 114,768,000,000 cubic feet.
The difference, or 44,196,000,000 cubic feet, is the
volume to be retained in reservoirs, to control such
a flood and render it harmless.
  This quantity is equal to the discharge of a five
feet stage in fifty days.
  The possibility of controlling the floods of the
Ohio, and maintaining a sufficient depth of water
for the purposes of navigation, has apparently been
proved, by figures, with the clearness of demonstra-
tion; but a cautious prudence may still find room
for doubt; and in looking forward to the various
contingencies that may arise, there is reason to fear
that, in this case, as in many others, the deductions
of theory and the results of practical operations may
not be entirely consistent.
  It hts been shown, by the practical example
above cited, that in the year 1841, the retention of
44,196,000,000 cubic feet of the March flood would
have kept the rise at Wheeling within the moderate
limits of twenty-five feet. And this would have

 


17



required a reservoir, or a number of reservoirs, equal
in capacity to an area of four miles square, or six-
teen square miles, with a depth of one hundred feet.
  Now, it must be observed that these reservoirs, it
constructed, cannot secure the desired object unless
they are entirely empty before the flood com-
mences-if partly filled, a corresponding increase of
capacity will be required.
  The question will naturally arise: Is it possible
in practice so to operate these reservoirs as to insure
at all times the conditions upon which their efficacy
depends Can we have them always empty before a
flood, and always full in advance of a period of
drought Would not the attempt to fulfil these
conditions require the performance of impossibili-
ties Wouild it not demand a prescience with which
mortals have not been favored 
  It is not necessary to enlarge upon a point which
is so self-evident. However capacious the reservoirs
may be-were they capable of holding ten times the
volume which forms the injurious excess in floods,
they cannot retain this volume if previously filled
by rains, and cases may arise in which they would
not secure the desired object; the remedy cannot be
infallible.
  But there are other difficulties. The maintenance
of a sufficient stage of water for the purposes of
navigation requires a constant depth of not less than
six feet. No improvement should be considered as
satisfactory which does not secure this as the mini-
      2

 



18



mum depth beyond peradventure. A smaller depth
will, of course, be an improvement upon the present
dry channel, but the requirements of commerce, the
interests of the nation, can be satisfied with nothing
short of a permanent 6 feet stage, and 10 feet would
be still better. Will the reservoir plan provide a
constant depth of 6 feet We will examine this
question.
  The present year, 1854, has witnessed a longer
continuance of drought and of suspended navigation
than, perhaps, any other upon record. For a con-
tinuous period of six months, the larger packets
have been tied up. The records of this year would,
therefore, be peculiarly valuable, as the basis of a
calculation, and the writer has requested a copy of
the Wheeling observations; but, in the absence of
these data, we will take the results of the year 1845.
  It has been shown that the total discharge of the
Ohio at Wheeling in this year was
           555,482,000,000 cubic feet;
and, by an application of Mr. Ellett's formula, this
would have been sufficient to maintain a uniform
flow of 7 feet on the Wheeling bar. To secure this
uniform flow, it is evident that no excess over 7 feet
could have been permitted at any period in the
year-an obvious impossibility.
  With a uniform depth of 6 feet upon the Wheel-
ing bar, the annual discharge would have been
           424,860,000,000 cubic feet;
leaving    130,622,000,000 cubic feet
as the surplus to escape in stages exceeding 6 feet.

 



19



  We have before us a record of the observed depths
of water on the Wheeling bar daily. From these
observations the discharge can be readily obtained.
  By estimating the discharges over and under 6
feet for each period of fluctuation, starting on the
supposition that the reservoirr were empty at the com-
mencement of the observation.s, deducting from the ex-
cess of one period the deficiencies of the next, and
continuing the calculation until the end of the year,
allowing, also, for the escape of the excess over 6
feet, the maximum capacities of the reservoirs would
be ascertained. But, as our present object-which
is the illustration of a principle-does not require a
close examination of details, it will be sufficient to
take the monthly, instead of the daily discharges.
  The average monthly discharge, with 6 feet
depth of water, would be
            35,405,000,000 cubic feet.
The actual average monthly discharge was
            46,290,000,000 cubic feet.
The difference is
            10,885,000,000 cubic feet.
                                      Cubic feet.
In the month of January, the ac-
  tual discharge was .     .    . 93,843,000,000
In February     .     .            77,542,000,000
In March   .    .     .    .    . 136,774,000,000

Total for 3 months above average 268,159,000,000
Deduct discharge at 6 feet stage  106,215,000,000



. 161,944,000,000



Difference  

 



20



                                     Cubic feet.
During, the months of April, May,
  June, July, August, and Sep-
  tember, the discharge was below
  the 6 feet average, and amount-
  ed to    .    .    .    .    . 136,585,000,000
The discharge of a 6 feet stage
  during the same time would
  have been     .    .    .    . 212,430,000,000
The deficiency to be supplied by
  the reservoirs would have been  75,845,000,000
  The capacity of the reservoirs to retain this quan-
tity of water, with an average depth of 50 feet,
would be 55 square miles.
  By examining the record of January, it appears
that the excess in that month, over the discharge of
the 6 feet stage, was 65,438,000,000 cubic feet, or
only 10,407,000,000 less than sufficient to fill the
reservoirs of the capacity of 75,845,000,000 cubic
feet.
  During the next month, the discharge being
77,542,000,000 cubic feet, the reservoir would have
been filled, and 31,730,000,000 excess over the 6
feet discharge would have been wasted.
  In this position of affairs, the March floods find
the reservoirs already overflowing, and not a drop
of the 136,774,000,000 cubic feet-the greatest dis-
charge and highest flood of the year-could have
been retained. The reservoirs would have been
utterly powerless, in this case, to hold back any por-

 



21



tion of the flood or afford any protection against
inundation. It is true that the maximum rise this
year did not exceed 24 feet, but had it been 40 feet
the result would have been the same-the reservoirs
could have afforded no protection, for the simple
reason that they were already filled.
  But suppose the March floods had been antici-
pated, and that, by suitable arrangements, the accu-
mulations of the previous month had been dis-
charged; in that case, the flow of March would have
filled the reservoirs, furnished the 6 feet discharge,
and an excess of 36,000,000,000 cubic feet would
have been wasted. This is precisely the result de-
sired, and, if it could always be secured, the reser-
voir plan would fully satisfy the expectations of its
advocates, in securing the double object of retaining
the injurious excesses during floods, and furnishing
sufficient depth for navigation in seasons of drought.
But the practical operation of the system depends
too much upon conjecture. Should the reservoirs
be emptied in anticipation of a flood, and the flood
be delayed, suspended navigation would be the con-
sequence.
  The only protection against such results, and the
only way of rendering the reservoir plan practically
efficacious, appears to consist in constructing the
reservoirs of sufficient capacity not only to supply
all the water required for navigation, but also to
retain, in addition to this, the excess necessary to
prevent injurious overflows.

 



22



  It has been shown that the records of 1845 give
75,845,000,000 cubic feet as the capacity required
during that year to supply a six feet stage of wa-
ter on the Wheeling bar. The records of the pre-
sent year would probably indicate that more than
100,000,000,000 would be necessary. Mr. Ellett
has stated that floods not exceeding 25 feet at
Wheeling do no serious damage, and that of the
flood of 1841, 44,196,000,000 cubic feet should have
been retained in reservoirs to afford the necessary
protection.
  It would appear, therefore, that, to insure sufficient
water for navigation and restrain excessive floods, a
reservoir capacity of about 140,000,000,000 cubic
feet should be provided, and so contrived that the
flood excess would be discharged as quickly as pos-
sible after the waters commenced to fall.
  To retain this quantity, the aggregate area of the
reservoirs, with an average depth of 50 feet, would
be 50 square miles.
  It has been proposed to construct these reservoirs
upon the tributaries near the sources of the streams,
where the lands are of comparatively little value.
  The time has passed when lands in the valleys of
the mountain streams of Pennsylvania can be con-
sidered valueless. The great amount of surface
which is covered with rocks, or is too steep or too
barren for cultivation, adds proportionately to the
value of the bottom lands, where all the farms, and
where the forges, rolling-mills, and factories are

 


23



located. As no careful examinations have been
made to determine whether a sufficient number of
such locations exist, it will not be safe to assume
their existence as a fixed fact, and erect the super-
structure of a vast system of improvement upon
such a foundation. It is also proper to observe that
a long distance intervenes between the city of Wheel-
ing and the proposed locations of the reservoirs; a
large portion of the volume of the stream would be
due to accessions between these points, and if located
too near their sources amongst the mountain gorges,
the necessary supply to fill the reservoirs might
sometimes be deficient.
  But suppose all these conditions can be fulfilled,
and that locations for reservoirs can be found with
a sufficient supply of water and moderate damages
for the destruction of property by overflow, how
many reservoirs will be required to answer the pur-
pose
  This problem cannot be solved by any data in
the possession of the writer, but if the valleys near
the sources of the Alleghany, Monongahela, and
Youghiogheny are similar in their main features to
the valleys of Conemaugh, Black Lick, Yellow Creek,
and others, on the west slope of the Alleghanies,
with which he is better acquainted, it may be con-
sidered that the average width of the pools will not
exceed one-third of a mile, allowing ' feet fall to
the mile, and the dams to average 30 feet in height.
The cubic capacity of one of these pools would be

 



24



836,352,000 cubic feet; to retain the amount of
140,000,000,000 cubic feet would require 175 such
reservoirs with dams of 30 feet.
  If the dams should be increased in height, a
smaller number would suffice, but the expense of
each dam, with its sluices and machinery for dis-
charging the waters, would be increased.
  It is doubtless true that in ordinary seasons reser-
voirs of half the capacity here indicated might be
sufficient to maintain a 6 feet stage in the Ohio; but
it is necessary to provide for extreme cases, and it
is doubtful whether security against floods and
droughts, at all times, could be insured with a less
liberal provision.
  It is not probable that sites for 175, or even for
75 reservoirs, could be found near the sources of the
streams which form the Ohio.. If constructed at all,
they must be commenced at points not very remote
from Pittsburg, in which case the damage to pro-
perty from overflow would be largely increased.
  These considerations, if they are not based upon
sufficiently reliable data to demonstrate that the
reservoir plan by itself is inadequate to fulfil all the
requirements of the improvement, will, at least, be
sufficient to excuse the writer for entertaining and
expressing doubts of its practicability and success.

 


25



                   SLACKWATER.

  We propose now to examine the effects that would
be produced by dams in the Ohio, and the advan-
tages and disadvantages of a slackwater navigation.
  The improvement of a navigation by means of
slackwater is not an untried experiment; it has been
tested upon two of the tribu