IMPROVED MEANS FOR UTILIZING THE RISE AND FALL OF THE TIDE AS MOTIVE POWER
Year: 1879

page_text: LETTERS PATENT to Alexander Melville Clark, of Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IMPROVED MEANS
FOR UTILIZING THE RISE AND FALL OF THE TIDE AS MOTIVE POWER." A
communication from abroad by Margaret Jane Courtenay, of Idlewild, Cornwall-
on-the-Hudson, in the County of Orange, and State of New York, United
States of America.
Sealed the 28th February 1879, and dated the 1st January 1879.
COMPLETE SPECIFICATION filed by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 1st January 1879.
ALEXANDER MELVILLE CLARK, of Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVED MEANS FOR UTILIZING THE RISE AND FALL OF THE
TIDE AS MOTIVE POWER." A communication from abroad by Margaret Jane
Courtenay, of Idlewild, Cornwall-on-the-Hudson, in the County of Orange, and
State of New York, United States of America.
The means heretofore employed for utilising the rise and fall of the tide have
only furnished power intermittently, and but for a short time during each tidal
oscillation. This limited duration of power has been the more objectionable from
the fact that it could not be made to conform to any systematic division of recog-
nised working hours.
The advantage of the present Invention over any other heretofore employed for
the utilisation of the tidal fluctuations as a motive power is that the oscillations of
the tides are convertible into a constant, uniform, and unlimited hydraulic power,
the power being limited only by the areas of the basins herein-after described and
the height of the tidal oscillation. By the means of this Invention the power is
available incessantly, or may be stopped and started at any hour of the day or night
without reference to the state of the tide.
.
In order that the Invention may be more readily understood, I have illustrated
the means employed in the accompanying Drawings, and will proceed to describe
the Invention in detail with reference thereto. Similar letters of reference indicate
like parts in all the Figures.
Figure 1 is a part sectional plan view of the basins; Figure 2 is an elevation of
the sea face of the same; and Figure 3 is a vertical longitudinal section of the
same..
Figure 4 is a graphic delineation of the varying levels of head and tail water, as
obtained by this Invention, the constant difference between which is the source of
the power.
A is a dry basin whose bottom is a low tide level, the tops of its walls being a

page_text: few feet above high spring tide level.
are at half tide level, and the tops of
basin A.
B are two wet, basins the bottoms of which
their walls at the same level as those of the
The comparative areas of the three basins A, B, B, are such that the conditions
herein-after set forth may be fulfilled, a suitable per-centage being added for the
contingencies of tidal irregularities.
C, C, are two tunnels between the dry and wet basins, and parallel with them,
with their floors at low tide level, and the crowns of their arches at the level of the
bottoms of the wet basins B, B, opening at the one end into the open tide, and at
the other end into the supply basin or head reservoir D, and also into the tail
basin E.
The two tunnels C, C, are constructed to carry off the tail or waste water from
the wheel or other motor from low tide to half tide, or to that stage of tide when
it shall reach the lower part of the wheel or motor in rising, and between the
said limits in falling. The two tunnels C, C, are constructed for the further
purpose of supplying water to the wheel or motor from the direct tide outside of
the basins during the rise of the tide from any desired point above the wheel or
motor to high tide and back to the said point in falling. The wet basins B, B,
are designed to supply water to the wheel or motor from the time that the tide
shall leave the level of the bottoms of the said basins B, B, in falling until its
return to the same point in rising, or such portion of that time during which water
shall not be supplied by the two tunnels C, C.
The dry basin A should be constructed with an area which shall be adequate to
enable it to contain, when filled to the level of the wheel or motor, any or all of the
water which may pass through the said wheel or motor from the time that the tide
passes the level of the said wheel or motor in rising until it passes the same point
in its next consecutive fall, or during such portion of that time as the tail water
shall not be discharged through the tail basin E and the two tunnels C, C, so that
the said dry basin A may receive all the water which shall pass the wheel or motor
during that portion of the rise of the tide and of its next consecutive fall, when it
shall be at such height outside the basins as to prevent the tail water from the wheel
from being discharged through the tail basin E and the tunnels C, C.
In the lower part of the sea wall of the dry basin A is formed a gate a¹ with
its sill at the level of low tide, through which all water accumulated in said
dry basin A may be discharged into the sea at each ebb of the tide. In the sea
walls of the wet basins B, B, are formed gates b', b¹, with their sills at half tide,
through which the said wet basins B, B, may be refilled at each rise of the tide;
the said basins B, B, being constructed of a capacity adequate to supply the wheel
or motor during that period of time when it shall not be supplied by the tunnels
C, C. In the lower part of the inner walls of the wet basins B, B, are formed gates
62, 63, opening into passages F leading to and opening into the head basin or
reservoir D, or the said wet basins may open directly into the said head basin D.
In the wall of the tail basin E are formed gates el, e¹, opening into the tunnels C, C;
and in the walls of the head basin D are formed gates d, d, leading into the said
tunnels C, C. The tail basin E is constructed with its bottom on the level of the
bottom of the dry basin A, and is separated from the said dry basin A by a wall of
such height above the wheel or motor as to enable one to control the tail water
passing through the said wheel or motor, and to discharge the same, either into the
sea through the tunnels C, C, or into the dry basin A.
In the lower part of the wall between the dry basin A and the tail basin E is
formed a gate a²; the method of operation is as follows:-At ebb tide the gate a'
of the dry basin A is closed, the gates d¹, d¹, leading from the tunnels C, C, into
the head basin D are opened, the gates e¹, e¹, leading from the tunnels C, C, into the
tail basin E are closed, and the gate a leading into the dry basin A is opened. The
head basin D is now in free communication with the tide, and the level of the
water in it rises accordingly. When the level of water in the head basin D has

page_text: reached a working head above the wheel or motor, which is placed upon a bench or
stand in the tail basin E, it is turned on, and the power commences. The water
is now supplied from the direct tide through the tunnels C, C, and the bead basin D,
and is discharged through the tail basin E into the dry basin A.
This arrange-
ment continues as the tide rises.
At or before high tide, the gates 61, b', of the wet basins B, B, are opened, the
gates 62, 62, leading into the head basin D being closed. At the turn of the tide,
the gates b', b', are closed, and the tide descends, leaving the wet basins B, B, full.
When the tide in its fall reaches the level of the working head, the gates d', d',
connecting the head basin D with the tunnels C, C, are closed, and the gates 6º, 6º,
leading from the wet basins B, B, to the head basin D are opened.
The
The wet basins B, B, now supply the water, the discharge being as before into.
the dry basin A; when the tide in its fall reaches the level of the wheel or motor,
the gate a leading from the tail basin E into the dry basin A is closed, and the
gates e, e¹, leading from the tail basin E into the tunnels C, C, are opened.
discharge is now into direct tide through tunnels C, C, the supply still coming from
the wet basins B, B. At ebb tide the gate al is opened, and the contents of the
dry basin A are discharged into the sea. At the turn of the tide the gate a¹ is
closed, and the dry basin A remains empty, the discharge being still into direct
tide. When the tide rises to the level of the wheel or motor, the gates e', e¹,
leading from the tunnel C, C, into the tail basin E are closed and the gate a²
leading from the tail basin E into the dry basin A is opened. The discharge is
now into the dry basin A, and the supply is from the wet basins B, B, as before.
When the tide again reaches the head level, the gates are placed as in the first
instance, and the operation is repeated.
It will be observed that by this means a constant, uniform, and unlimited
hydraulic power is obtained, the only limit being the areas of the basins, and the
height of the tide.
In the chart shown in Figure 4, the shaded band G represents the height of
available head. The scale H of division marks at the bottom of the chart
represents the hour scale of the tide, and the width of the band G at any point
on the scale H is the available head at that time.
The upper full line I, J, K, L, indicates the varying level of the head water, the
lines J, J, and K, L, indicating the head level while the wet basins B, B, are
emptying, and the curved line J, K, indicating the head while supplied by the
direct tide, the wet basins being filled while the head is approaching the highest
point of the curve, and remaining full while the head passes down the descending
arc of the curve. The lower full line M, N, O, P, indicates the varying level of the
tail water, the line M, N, indicating the level while the dry basin A remains
empty; the line N, O, indicating the level while the dry basin A is filling, and the
line O, P, indicating the level while the dry basin A is emptying. By this chart
the operator can tell at a glance, at any hour of the tide, what available head he
may have at that time.
Having described the nature of the Invention, and the manner of performing the
same, I declare that what I claim as new, and desire to secure by Letters Patent
is,-
1st. The combination of the dry basin A and the two wet basins B, B, with each
other, in the manner and for the purposes substantially as set forth.
2nd. The combination of the dry basin A, the two wet basins B, B, and the two
tuunels C, C, running parallel with the said dry basin A with each other, in the
manner and for the purpose substantially as set forth.
3rd. The combination of the dry basin A, the two wet basins B, B, the two
tunuels C, C, the head basin D, and the tail basin E with each other, in the manner
and for the purpose substantially as set forth.
4th. The means for disposing of the tail water from the wheel or motor at all
stages of the tide, substantially as set forth.

page_text: 5th. The means for supplying head water to the wheel or motor at all stages of
the tide, substantially as set forth.
In witness whereof, I, the said. Alexander Melville Clark, have hereunto set
my hand and seal, this First day of January, in the year of our Lord One
thousand eight hundred and seventy-nine.
A. M. CLARK. (L.S.)