xt759z908v9g https://exploreuk.uky.edu/dips/xt759z908v9g/data/mets.xml Shaler, Nathaniel Southgate, 1841-1906. 1877  books b96-12-34908169 English Stereotyped for the Survey by Major, Johnston & Barrett, Yeoman Press, : [Frankfort, Ky. : Contact the Special Collections Research Center for information regarding rights and use of this collection. Geology Kentucky Maps. Topographical surveying Kentucky Maps. Description of the preliminary topographical and geological maps of Kentucky  : edition of 1877 / by N.S. Shaler. text Description of the preliminary topographical and geological maps of Kentucky  : edition of 1877 / by N.S. Shaler. 1877 2002 true xt759z908v9g section xt759z908v9g 










GEOLOGICAL SURVEY OF KENTUCKY.

         N. S. SHALER, DIRECTOR.



       DESCRIPTION

             OF THE

PRELIMINARY TOPOGRAPHICAL AND GEOLOGICAL



MAPS



OF



EDITION OF 1877,

BY N. S. SHALER.



PART VI. VOL.



III. SECOND   SERIES.



KENTUCKY,



347 A 348

 This page in the original text is blank.

 









DESCRIPTION OF THE PRELIMINARY TOPO-
        GRAPHICAL MAP OF KENTUCKY,
                  EDITION OF 1877.


                      INTRODUCTION.
  This map is designed especially as a record map for the use
of the Kentucky Geological Survey, and in order to fit it for
that use contains some peculiarities which require explanation.
It will be noticed that the names of towns are, in some cases,
limited to the county town and other important towns of each
county. This has been done in order to leave more space for
the notes of the officers of the Survey. Subsequent editions
of this map will give more of these local names. Special
efforts have been made to secure the names and direction
of flow of all the streams. Their relative size is also given,
with an approximation to accuracy,by the width of the lines
which designate them. The several river systems are distin-
guished from each other by the shading of the surface.
  It will be observed that there has been no effort made to
represent the relative level of different parts of the State by
indications showing the hills and mountains. The reason for
this is, that, except in about five thousand square miles of
the surface where the special topographical work of the Sur-
vey has been completed, no data exist for making such
a map. In this, as in all other topographical work, the Ge-
ological Survey is at a very great disadvantage, compared
with similar undertakings in other States. Kentucky never
received a survey after the plan of the other States whose
public lands belonged to the General Government, but has
remained to this day without any other basis for a map than
has been furnished by various surveys made for railways and
other public improvements, together with the various military
                                                       349

 

DESCRIPTION OF THE PRELIMINARY



surveys made during the late civil war. These were com-
bined during the later years of the war by the orders of the
generals commanding in succession this department, and from
this military map of Kentucky and Tennessee the topogra-
phy of the appended map has in good part been taken. The
railroads are laid down from their several surveys, and the
rivers are from the surveys that have been made at sundry
times. It is intended that this map shall be supplemented by
successive editions, giving the connections and improvements
which may be made from year to year, during the time re-
quired to accumulate the materials necessary to form a larger
and better map of the State.
  It will be seen that the map is made on the projection known
as the projection on the cone, the meridians being drawn par-
allel to each other. This arrangement, though objectionable
on some accounts, is the most convenient for all purposes:
the distortion it brings about is not worthy of notice in an
approximative map such as this. It is the projection adopted
in the military map which has furnished the general plan of
this. The indication of the meridians are not to be taken as
definite, or by any means certain for their positions. They
are doubtless nearly true where they cross the Tennessee line;
and the base lines furnished by the old Survey serve to help
the adjustments; but, on the whole, they are only rude ap-
proximations. In order to facilitate reference to the map, it
will be seen that the spaces of fifteen inches each have been
numbered for the meridians and lettered for the parallels.
This will make the designation of any particular spot a mat-
ter of comparative facility.
  The average error of the geological position of the points
given on this map is great. The triangulation work under
way has proven, that for the southeastern part of the area the
error of position of points in relation to each other is so great,
that any two points given as one hundred miles apart on the
map may be no further than ninety-seven, or as much as one
hundred and three miles from each other. The error in com-
pass course of the lines joining any two points is proportion-
350



4

 

TOPOGRAPHICAL MAP OF KENTUCKY.



ately quite as great. Successive editions of this map will
progressively eliminate these errors.

PRELIMINARY DESCRIPTION OF THE TOPOGRAPHY OF KENTUCKY.
  To aid in the understanding of this map, as well as to give
a general idea of the features of the country that are not rep-
resented by it, I shall give a brief account of the surface feat-
ures of the country, and some explanation of their connection
with the underlying rocks. This will require a short statement
of the geology of this district. In this statement all details
not necessary to a general understanding of the subject will
be carefully omitted.
  The whole of the State of Kentucky lies within the valley
of the Mississippi river, and about all of it within that section
drained by the Ohio and its tributaries.  Scarce any other
State in this country has a drainage so entirely limited to one
direction of flow. Every part of it, save a small strip along
the Mississippi, lies on the southern tributaries of the Ohio
river, the meanders of which river form nearly seven hundred
miles of its northern boundary. This river, one hundred and
forty miles of the Big Sandy, and about fifty miles of the Mis-
sissippi, below its confluence with the Ohio, constitute the
river boundary of the State, and form the whole of its west,
northwest, north,. and northeast lines. The southeast face is
formed by Cumberland Mountain and some of its associated
ridges, and the south face by an arbitrary east and west line,
extending from Cuimberland Gap to the Mississippi river, with
a few irregularities in its course.  Thus the forty thousand
square miles of area is inclosed in an irregular pentagon, four
sides of which are natural boundaries of river or mountain
range, and only the fifth is a conventional boundary. The
topography of the State is as simple as its outline. The Ohi6
river, so prominent a feature in its map, is the key to most of
its surface. All except about one eighth of its area, situated
in the southeast corner of the State, lying within a line ex-
tending from the north end of Floyd county to the southwest
side of Whitley county, may be regarded as a part of the
                                                           3sI



5

 


DESCRIPTION OF THE PRELIMINARY



valley table-lands of the Ohio, varying in character according
to their underlying rock, but owing their form almost entirely
to the cutting action of the rivers, acting upon rock which has
never been thrown into great mountain folds. In the forma-
tion of this surface there have been, with slight exceptions,
no other factors than the hardness of the rocks and the energy
of the wearing agents-running water and frost. This has
given a surface in general rather level, but elevated high
above the plane of the main streams, which cut for themselves
deep valleys with precipitous sides, often true canions in their
form. The height of these elevated plains above the sea,
and above the drainage, Varies a good deal, according to their
position in the State and the nature of the rock in which they
have been excavated. At Hickman, the base of the topogra-
phy may be placed at about two hundred and fifty feet above
the sea; rising from twenty feet in the lowlands to one hundred
feet in the small area of Tertiary deposits in the Chickasaw
plateau. From this section, towards the eastward, there is a
continual increase of height. This may best be represented
by drawing radiating lines from the mountain area of South-
eastern Kentucky in every direction to the Ohio, this moun-
tain section being the stream centre of the South Ohio area,
all its southern tributaries pointing towards that region. The
drainage levels rise with great uniformity in that direction;
the only great differences of level being caused by the change
in the height of the plateau between the streams. Whenever
these lines cross the line of outcrop of the different forma-
tions, there is apt to be a sudden change in the character of
the surface, and often a distinct cliff-like ridge occurs. Mul-
draugh's Hill and Big Hill are good examples of this structure.
Many of these lines of escarpment or outcrop are commonly
represented as mountains on the several maps which have
been published. They differ from ordinary hills, inasmuch as
they are sloped on only one side; their face may be cut so as
to make many steep valleys and isolated hills; but as a whole
the outlines are only accidents connected with the wasting of
the escarpment. They also differ from the ordinary hills in
352



a

 
TOPOGRAPHICAL MAP OF KENTUCKY.



being steep-faced on one side only, while ordinary mountain
ridges are steep-faced on their several sides. These escarp-
ments, again, differ from mountains of elevation in having the
rocks that compose them lying in essentially horizontal posi-
tions, while in the mountains the disturbance to which the
rocks have been subjected have done much to give them their
form and elevation.
  The surface of the greater part of Kentucky having been
in the main the product of erosion, quite without the com-
plication given by the various abrupt tiltings occurring in the
mountainous regions of the globe, it is naturally found to lie
in these comparatively level table-lands, which always mark
horizontal strata. The data does not yet exist for determining
the height of every part of the State; but, from the before-
described base at the northwest corner, we rise to about five
hundred feet for the table-land of the Carboniferous of West-
erm Kentucky, between the Cumberland river and the Louis-
ville and Nashville road. Going still further east, the gain in
height is continued to a line drawn from Lexington southwest-
erly to the Kentucky boundary, where the surface attains to a
height of about one thousand feet above tide-water; but the
table-land rises more rapidly than the stream-beds, so that the
valleys of the stream-courses are deeper as we go towards this
central region. Passing this line, extending south from Lex-
ington, we come into a region where, except near the Ohio,
the rise in the stream-beds continues, while the table-lands
rather lose in height The cause of this is found in an impor-
tant though comparatively slight change in the position of the
rocks beneath this line, extending from Lexington towards
Nashville. This line extends along the top of a low ridge,
formed at a very early date by a broad folding of the rocks of
the earth's crust. This ridge seems to have been more than
four hundred miles long, about a hundred miles in its east and
west transverse measurement, and rising to a height of from
three to eight hundred feet. At Cincinnati and at Nashville
this ridge had its greatest height. In the country through
which the Green river passes lies the lowest part of the ridge.
    VOL 111.-23                                           353



7

 

DESCRIPTION OF THE PRELIMINARY



The ridge extends some hundred miles or more to the north
and south of the highest points at Cincinnati and Nashville.
In general character it closely resembles the other mountain
ridges of the Allegheny system: its course is the same, and
the greater elevation of the ridge near either extremity is
also a character in which it resembles the mountains on the
east.
  This Cincinnati-Nashville axis causes the central part of
the State to rise above the level it would otherwise occupy.
East, south, and west of the Lexington summit is a semi-cir-
cular trough, extending from the Ohio river, in Mason and
Lewis counties, around the outcrop of the soft beds of the
Devonian shale, which lie just over the Cincinnati Group,
through the counties of Lewis, Fleming, Bath, Montgomery,
Estill, Madison, Lincoln, Marion, Nelson, Bullitt, and Jeffer-
son, to West Point, on the Ohio river. This depression is
due to the wearing out of the soft beds of the Devonian shale,
and, in a less degree, to the erosion of the soft beds which lie
at the top of the underlying Silurian beds, and the base of
the overlying Waverly shale. The depression of this valley
is very slight, provided we reckon from the top of the highest
hills to the bottom of the lowest valleys. The hill-tops are
almost as high as those of the Silurian district, and the river
valleys fall, on the average, but little below the level of those
which lie over the broad Nashville-Cincinnati mountain; but
the hills in this section are apt to be mere knobs, capped by a
plate of the hard beds of the superior rocks which have worn
away. The valleys are relatively very broad. It often hap-
pens that a small rivulet that can not be ranked more than a
sixth-rate stream-one too small to require bridging on ordi-
nary roads-comes to have a broader valley than a stream like
the Kentucky river, where it cuts through hard rock.
  In general we may say that the table-land district of Ken-
tucky, which includes all its area except the small mountain
district before described, has its hill-tops about conformable
 For a fuller acc-unt of this ridge, see notes on the question developed in the explora-
tions of the Geological Survey, in this volume.
354



8

 

TOPOGRAPHICAL MAP OF KENTUCKY.



to an inclined plane sloping from the Ohio and Mississippi
upward towards Cumberland Gap, and only varies from this
uniformity of structure in the width and depth of its valleys.
  The distribution of the main rivers of Kentucky, though
simple and conformable to the general slopes of the country,
has some points of special interest which deserve mention.
It will be noticed that they all head in or near the mountain
mass in the southeast corner of the State, and pass on more
or less distinctly radiating lines towards the Ohio river, falling
into it at right-angles to its direction of flow. Extending our
view beyond the limits of the State, so as to take in the whole
system of tributaries of the Ohio, we then see that the main
drainage centre of that basin is found in the great system of
mountains and valleys belonging to the Appalachian chain,
within the boundaries of Eastern Tennessee and Virginia.
The Tennessee and the Cumberland originate well within
those mountain walls, and, limited by their barriers, flow to
the southwest, but, guided by the general slope of the rocks,
always pressing against their walls on the west, and taking
advantage of every weak place in the line to gain something
on their western journey. In this westward advance they
are aided by two elements in the structure of these moun-
tains: First, the frequent transverse breaks in the rocks of
the mountains caused by faults. Second, the successive low-
ering in the height of the valleys as we go to the westward.
Generally a good part of these mountain ridges consist of
limestones which caverns easily, and so readily begins a break
from one level to another. As the Tennessee begins far with-
in the central valleys of the Alleghenies, it has a long wrestle
with the mountains as it follows their general slope south-
ward, and their cross-slope to the westward, until it has quite
crossed the mountain.  It then turns at once to follow the
general trend of the valley of the Ohio. The upper Cum-
berland makes but one break across a mountain-that at the
gorge where it passes Pine Mountain. It then has to encoun-
ter the Cincinnati-Nashville axis, which causes it to keep away
                                                          3SS



9

 
DESCRIPTION OF THE PRELIMINARY



from its normal course until it passes that ridge, when it turns
towards the Ohio and becomes parallel to the Tennessee.
  The Green river does not get far enough east to feel any
influence from the Cumberland Mountains, and so follows the
normal course of the valley tributaries of the Ohio. The
same may be said of Salt river and of the Kentucky, save at
its very head. A few of the upper tributaries of the last-
named river lie within the disturbed region of the Cumber-
land Mountains. As shown on the map, the courses of these
mountain-bordered tributaries depart sharply from the trends
of the other branches. These tributaries of the Kentucky,
which fall within the mountain lines, are all quite small, none
of them exceeding twenty miles in length. The Licking
river, which occupies only a limited area between the Ken-
tucky and the Little Sandy and the Chatterawha or Big
Sandy, does not attain to the disturbed belt of the mountains,
and the other smaller streams between the Licking and the
eastern border of the State are also limited to the table-land
region. The Chatterawha or Big Sandy river differs in some
important regards from the other Kentucky rivers, and from
most of the main tributaries of the Ohio, especially in the
peculiar feature of having one branching,where the stream is
divided into two equal forks. This unusual arrangement is
not readily explained, from our present inadequate informa-
tion as to the structure of the rocks in that region. Only the
westernmost of these branches has its head waters within
Kentucky.  The uppermost tributaries of this branch turn
abruptly into the trends of the Cumberland Mountains, flow-
ing to the northeast until they escape from the mountain
troughs.
  We have now considered the relation of the Kentucky riv-
ers, and seen that, while their head waters are to a certain
extent involved within the mountain valleys of the Appalach-
ian system, these streams as a whole, at least within her bor-
ders, are quite purely table-land rivers, and conform to the
same laws as those tributaries which flow into the Ohio from
the north. We may now pass to the details of their structure.
356



IO

 

TOPOGRAPHICAL MAP OF KENTUCKY.



  There are some peculiarities of the Kentucky streams
which, though not evident on the map, are quite important,
both in an economic as well as in a scientific way. The most
important point is the rate of fall observable in the course of
the streams. The average fall of the Ohio, Tennessee, and
Cumberland, within the limits of Kentucky, is probably less
than six inches to the mile. The strictly Kentucky rivers
have much greater rate of descent, on account of their rel-
atively shorter courses. The Big Sandy river, for instai.ce,
falls half as much in its short course as the Tennessee in its
course of thrice as many miles. The average fall of the Ken-
tucky, Licking, and Sandy rivers is about one foot to the mile;
but this is distributed in a very unequal way-the fall ranging
from an average of three feet on the upper half to six inches
or less on the lower half. The northern tributaries of the
Ohio have about double the rate of fall of its southern afflu-
ents. This less rapid inclination in the southern tributaries
of the Ohio is a curious feature, and one not readily explained,
save in a general way. It is, in good part at least, due to the
fact that the drainage slope on the south is far wider than on
the north; so that, while the rivers have a greater height for
their descent, they have also a much greater proportionate
distance in which to accomplish their journey from their source
to the main stream. Besides this, they come from a region
having a much greater rainfall than those on the north of the
Ohio, and thus, being larger streams, have in time cut their
beds deeper into the rock foundations.
  These features give to our Kentucky rivers a great economic
value-a value not possessed by any of the northern tributa-
ries of the Ohio, and by none other of its southern streams,
except the Kanawha and Monongahela rivers, which have the
same features. Of all the tributaries of the Mississippi, these
rivers which pass through Kentucky are the most suscepti-
ble of improvement, and, when rendered navigable, the most
likely to be the means of developing important industries.
Their channels are well defended by rocky banks, which afford
excellent foundations for dams, and their head waters are
                                                          357



I I

 

DESCRIPTION OF TIHE PRELIMINARY



admirably suited for the storage of water to insure a constant
navigation. When they have received that improvement of
which they are so susceptible, they will afford at least two
thousand miles of slack-water navigation, of which more than
one half will be through the richest field of coal, iron, and
timber that is afforded by any part of this country. They are
the natural avenues to a vast store of the most important bases
of industry.
  Before leaving the consideration of our rivers, it is well to
notice the way in which the evenness of their distribution
shows the uniformity of the geological structure of Kentucky.
They,one and all, originate in the beds which belong in the
Carboniferous series of rocks. With the exception of Green
river, all of them have their sources in the rocks containing the
coal beds. This river has its head waters in the Sub-carbonif-
erous limestone; but, as if to make amends for the loss the
river has received from the wearing away of the coal beds
through which its head waters once flowed, its course is so
laid as to pass through the important coal basin of the west-
ern half of the State, where, for a hundred miles or more, it
is bordered by an admirable coal field.
  Close consideration of the map will show that there are
considerable areas in the district it represents where there is
a curious absence of streams: one of these, and the largest,
lies within the limits of the counties of Warren, Edmonson,
Barren, and Hart. In one direction the traveler may pass for
about fifty miles without encountering a single surface stream.
The whole drainage of the country is underground, through
the vast and interminable system of caverns which honeycomb
the whole area. The water falling on the surface courses for
a few hundred feet, and then plunges downward through a
sink-hole into the subterranean ways below. On the surface
we have either a plain pitted all over by these sink-hole en-
trances into the caverns below, or else a system of ridges and
valleys which have survived the loss of the streams that
once flowed through them, and their water-courses are now
replaced by rows of sink-holes, which swallow the streams
358



12

 


TOPOGRAPHICAL MAP OF KENTUCKY.



before they become more than trifling rills. For each of the
extinguished surface streams which, as the sandstones of the
coal period in which they once flowed were cut away, dis-
appeared in limestones below, there is an answering cav-
ern line, or rather a set of caverns, tier on tier, which mark
the successive down-working of the stream in the differ-
ent levels of the mountain limestone. There are several
other regions in the State where there are very extensive
caverns, but none so important as this.  Generally the
lesser streams alone have their courses subterranean, while
the considerable creeks flow in the open air, occasionally
sinking for a certain distance.  Breckinridge and a part
of the adjoining counties have this character, and near all
the outcrops of the Sub-carboniferous limestone it is gen-
erally found; so that the caverned area of the State, or the
region where the streams generally work for much of their
course underground, probably exceeds five thousand square
miles, or about one eighth of the whole surface of the State.
In some sections, as in the cavern district of Carter county,
the caves have been deeply worn down, so that they have
had their roofs much stripped away, leaving fragments of the
arches in the shape of natural bridges, which here, as else-
where, are always but the ruins of cavern vaults.
  The rivers of Kentucky, with few exceptions, and those
mainly in the mountain regions, occupy deep sunken valleys
with very steep walls. Within and below these walls we have
marks of the recent action of the rivers at various points
above their present plane.  Above their level the surface
gives us evidence that the rocks have been decaying in their
places for a very great time. Yet, upon these upper levels,
at a height of one, two, or even three hundred feet, we some-
times find river gravels, showing that the streams have worked
for great lengths of time in their present neighborhood; and
showing further, that, in the vast time that has elapsed since
the rivers flowed on these ancient beds, there have been no
agents at work which could efface their work. This, in itself,
                                                          359



I 3

 

DESCRIPTION OF THE PRELIMINARY



is evidence enough that the surface of Kentucky was not
swept by glaciers during the last geological period.
  The accompanying map of the river basins of Kentucky
will show the irregular way in which the surface of the State
is shared among the rivers. It is not easy to account for this
irregularity in the disposition of the streams away from the
mountain regions. Away from those disturbed regions there
are only slight irregularities in the rocks, which do not seem
to have any power of determining the range of a river basin.
Other explanations being wanting, it seems worth while to
suggest that the topography we have here may be inherited
from the conditions given by the beds in which it was formed.
Each generation of rivers is like a generation of living beings.
Its character depends not only on its own existing conditions,
but on the condition of those that have gone before. When
our streams were running on levels that are now hundreds, or
may be thousands, of feet above their present level, the rocks
they were cutting may have been disposed so as to give them
their present arrangement, and their present order may have
been inherited with little change.
  At certain points these local peculiarities of distribution of
streams are so great as to baffle conjecture. The drainage
opposite the mouth of the Sciota, in Lewis and Greenup coun-
ties, is a case in point. This drainage area is all sloped away
from the river for a considerable stretch along its banks, the
hills, six hundred feet high, shedding their water to streams
that only find their way to the main river after very devious
courses. Another puzzling case is that of the drainage on
the south side of the Kentucky river from Frankfort to Dick's
river. The head waters of Salt river take nearly all the water
of the region bordering the Kentucky on this part of its
course. A glance at the map will show that for nearly thirty
miles the head waters of Salt river run parallel with the Ken-
tucky, and at an average of less than ten miles from that
stream. It is not improbable that the fault system which
crosses the Cincinnati axis at this point is in some way con-
nected with this peculiar system of drainage, though I have
360



14

 

TOPOGRAPHICAL MAP OF KENTUCKY.



not yet been able to determine this point in a satisfactory
manner. It seems likely that the rivers have flowed for a long
time in the same general position where we now find them.
This is proved, not only by the ancient gravels at a great
height above the present high-water levels, but by such case
of clearly parallel channels as those of the Cumberland and
the Tennessee rivers. These run near each other for over
seventy miles of their course, the average distance apart in
this part of their course not exceeding ten miles, and being
for about a score of miles reduced to half that distance. If
either of these rivers had wandered greatly since they became
parallel to each other, the result would necessarily be their
union in one stream.
  The same limitations may be put to the wandering of the
upper Cumberland where it flows through Knox county. As
will be seen from the notes on the surveys made at the time,
it was proposed to direct the waters of the upper Cumberland
into Goose creek and thence into the Kentucky, the valley
of Goose creek lies considerably lower than the valley of
the upper Cumberland; so that the natural passage of the
Cumberland would have been directly to the southwest after
it passes through Pine Mountain and into the upper Ken-
tucky. If the Cumberland had ever swung to the north as
much as fifteen miles, since the establishment of the relative
height in their valleys, then it would necessarily have been
diverted from its present course into the channel of the
Kentucky.  As this difference in height in the Cumber-
land and Kentucky river valleys is due to the greater thick-
ness of the Conglomerate' in this section, it dates back to
a very early time. I am disposed to believe that the relative
levels of these valleys have been about what they are now for
a very long time; so the probability is that the Cumberland
has never wandered far enough to break into the slope of the
Kentucky.
  Although not one half the actual sinuosities of our rivers
are indicated in this preliminary map, it will be seen that their
course is exceedingly tortuous; far more so than the course of
                                                         36z



15

 

6            DESCRIPTION OF THE PRELIMINARY

the average American streams. Their comparatively gradual
descent is accounted for by this winding character. It is not
so easy to account for the windings themselves. It is likely
that this is the normal character of streams whose valleys have
never felt the tread of the glacial rivers, which necessarily
tend to take out the windings of the river in a very summary
fashion. Throughout New England and all other extensively
glaciated regions known to me, the. general character of the val-
leys is just what it is in those parts of the Ohio river system,
lying north of the Ohio, which have been subjected'to glacial
action. An ice stream working in the Kentucky or Licking
valleys would have made a broad U-shaped valley, instead of
the narrow V or cafion-shaped gorge. This existing structure
of our Kentucky valleys is a strong proof that, since they
began to occupy their present beds-that is to say, for the last
four hundred feet of their cutting-there has been no ice
action in their valleys.
  The tortuous character of our Kentucky rivers gives the
State more river front than occurs on any other region where
I have had the opportunity of making measurements. As
there is usually only about four hundred feet of fall to be ac-
complished from the smallest tributaries to the main Ohio, it is
readily seen that the head waters of the larger streams have
a very gradual fall. It also follows that the average rule of
fall of any stream is generally proportionate to the distance
it has to flow to find the Ohio. Many of the small tributaries
which fall into the Ohio, after a course of twenty miles or less,
fall more than half the distance that the Kentucky river does
from its uppermost head waters to its mouth, though the actual
distance traversed in all its windings is not less than four
hundred miles. As the amount of descent in the case of
the Kentucky river cannot be more than twice that of the
shorter stream, it is evident that its average fall is not over
one tenth that of the shorter stream. I believe it will be
found that the same length, measured on the head waters of
the Kentucky or other principal rivers, and on the small trib-
utaries of the Ohio, say those less than a score of miles in
362

 

TOPOGRAPHICAL MAP OF KENTUCKY.



length, will show a less rate of fall than on the shorter
stream. Although there is no evidence in the way of meas-
urement to show this fact, it may be inferred from the consid-
eration that, though the Kentucky at the Three Forks is over
five hundred feet higher than the Ohio at its mouth, the trib-
utaries for a great distance above that point fall at the gradual
rate of less than one and a half feet per mile. The length
of the confluents of the stream seem