IMPROVEMENTS IN AQUARIA AND APPARATUS CONNECTED THEREWITH
Year: 1873

page_text: LETTERS PATENT to Thomas William Kennard, of Number 7, Cromwell
Road, South Kensington, in the County of Middlesex, Civil
Engineer, for the Invention of "IMPROVEMENTS IN AQUARIA AND
APPARATUS CONNECTED THEREWITH."
Sealed the 10th October 1873, in pursuance of an Order of the Lord
Chancellor, and dated the 28th March 1873.
PROVISIONAL SPECIFICATION left by the said Thomas William
Kennard at the Office of the Commissioners of Patents, with his
Petition, on the 28th March 1873.
I, THOMAS WILLIAM KENNARD, of No. 7, Cromwell Road, South
Kensington, in the County of Middlesex, Civil Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN Aquaria
AND APPARATUS CONNECTED THEREWITH," to be as follows:-
The object of my Invention is to provide a means of causing the
water in an aquarium to be partially withdrawn and returned again
after being passed through a filtering medium, whereby a periodical

page_text: movement or circulation of the water is caused, combined with the
removal from it of impurities. It has also the advantage in marine
aquaria of imitating the ebb and flow of the tide.
In order to effect the above objects a tube open at the upper end
passes vertically upwards through the bottom of the aquarium to the
heighth intended as the limit to which the water is to be withdrawn,
the other end enters a vessel within a short distance of the bottom, and
the vessel is placed at such a level as that the whole of it is below the
level of the bottom of the aquarium. In the vessel into which the tube
enters, and below the orifice of the tube there is a filtering medium,
with a space between that medium and the bottom of the vessel.
Another tube leads from the vessel below the filtering medium, and
passes up through the bottom of the aquarium to the same heighth as
the first mentioned tube, having its end also open. I prefer to have
that part of both these tubes which is outside the aquarium made of
flexible material, and I cover the upper ends of both the tubes which
are in the aquarium with a grating or gauze to prevent the passing of
any foreign substance. The lower part of the first mentioned tube is
furnished with a valve which permits water to enter the vessel but not
to flow out, the lower part of the second mentioned tube has a valve
which admits of water flowing out but not flowing into the vessel. The
upper part of the vessel is closed and a part of its upper portion is made
similar to the bellows of a concertina and the capacity of that part which
is so constructed must be equal to the volume of water intended to be
withdrawn at any one time. The top of the vessel is forced down by a
weight or spring and the latter is put in action by a clockwork arrange-
ment.
"
The action of the above apparatus is as follows:-The aquarium being
filled to its maximum heighth the water flows out through the first
mentioned tube into the vessel and raises the top of it. As soon as the
top has arrived at its full heighth, and the requisite quantity of water
has consequently been withdrawn, the clockwork arrangement puts in
action the spring or weight, and depresses the top of the vessel. The.
valve at the bottom of the first mentioned tube prevents the water
escaping through it, it is therefore forced up through the second
mentioned tube back into the aquarium after having passed through
the filtering medium. As soon as the water is returned the clockwork
arrangement releases the spring or weight and the top of the vessel

page_text: rises again by the water passing down through the first mentioned
tube, the valve at the bottom of the second mentioned tube preventing
any flow of water from the aquarium into the vessel by the second
'mentioned tube.
SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said Thomas
William Kennard in the Great Seal Patent Office on the 11th
October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WILLIAM KENNARD, of No. 7, Cromwell Road, South Kensington, in
the County of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of March, in the year
of our Lord One thousand eight hundred, and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Thomas William Kennard, Her special
licence that I, the said Thomas William Kennard, my executors, admini-
strators, and assigns, or such others as I, the said Thomas William
Kennard, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there
after during the term therein expressed, should and lawfully might,
make, use, exercise, and vend, within the United Kingdom of Great.
Britain and Ireland, the Channel Islands, and Isle of Man, an Inven
tion for "IMPROVEMENTS IN AQUARIA AND APPARATUS CONNECTED THEREWITH,"
upon the condition (amongst others) that I, the said Thomas William
Kennard, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office on or before the Fourteenth day of October
One thousand eight hundred and seventy-three.
"
NOW KNOW YE, that I, the said Thomas William Kennard, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained

page_text: in and by the following statement, referenco being had to the several
Drawings therein referred to, and hereunto annexed.
1. The object of my Invention is to provide an apparatus for causing
the water in an aquarium to be from time to time partially withdrawn
from and (after being passed through a filtering medium) to be returned
again into such aquarium, whereby a movement or circulation periodical
or intermittent is caused, whilst at the same time impurities are removed
from the water so circulated.
My Invention has also the advantage in marine aquaria of imitating
in some measure the gradual ebb and flow of a tide. These results are 1
so effected as to render the same water available for an aquarium during
a long period without the necessity of a fresh supply of water.
2. One method of effecting these objects is as follows:-A tube, herein
distinguished as the discharge pipe and open at its upper end, passes
upwards through the bottom of the aquarium and may be carried to 1
the vertical height intended as the limit to which the water is to be
withdrawn, herein-after referred to as "the low limit." Such discharge
pipe is furnished with a valve or passes through a box furnished with.
a valve as herein-after mentioned, and the other end of the discharge
pipe enters a vessel or expanding tank placed either underneath or at 2
a convenient distance from the aquarium, but which vessel should be in
any case placed at such a level as to bring the highest part of such
vessel below the level of the lowest part of the aquarium. The expanding
tank is water-tight and is divided into two parts or sections by a filtering
medium which may be placed therein horizontally; one of such parts 2
or sections must be so constructed as to be capable of expanding or
contracting and so as to be of variable capacity, and this may be effected
by making the sides of the same part or section of gutta percha or
other flexible and water-tight material, but so that such material be not
injurious to the creatures contained in the aquarium, and forming such 3
part or section in the same manner as the expanding portion of a con-
certina; the other part or section of such expanding tank may be so
constructed as to be of a constant capacity. The expanding tank should
be so fixed by proper framework or otherwise that one plane therein,
which may be conveniently either the upper side or the lower side, should 3
be-constantly and permanently in the same position, but space must be
given to allow one side to be moveable through a sufficient distance so
as to allow the expanding tank to be expanded or contracted as far as,

page_text: necessary, as the case may require, and if the upper or the lower side
is fixed it will be convenient to have the opposite side (that is the lower
or upper side as the case may be) moveable. The capacity of the
expanding part (or parts) of the expanding tank should be such that
the excess in volume of the expanding tank when extended to its largest
capacity over its volume when compressed to its smallest capacity may
be equal to the largest volume of water which can be required to be
withdrawn at any one time from the aquarium. .
3. The discharge pipe enters one section of the expanding tank above
the filtering medium, and from the other section of such expanding
tank, i.e., below the filtering medium, another tube hercin distinguished
as the supply pipe passes through the bottom of the aquarium, such
supply pipe is furnished with or passes through a box furnished with
a valve as herein-after mentioned. With regard both to the discharge
pipe and also the supply pipe I cover that end thereof which is within
the aquarium with a rose or perforated metal plate or gauze so as to
prevent any foreign substance from passing from the aquarium into
such pipe. I find it convenient and in some cases necessary to make
portions of those parts of the discharge pipe and supply pipe which are
outside the aquarium valve boxes and expanding tank of flexible
material, for instance, of gutta percha or any other suitable material, so
that such material be not noxious to the creatures contained in the
aquarium. The valve in the discharge pipe or the box connected
therewith is so placed as to allow water to flow only from the aquarium
into the expanding cistern, but to prevent water from flowing through
such pipo in the opposite direction the valve in the supply pip or the
box connected therewith is so placed as to allow water to flow only from
the expanding cistern into the aquarium, but to prevent water from
flowing through such pipe in the opposite direction, as the tubes which
I employ for the discharge pipe and supply pipe are of small dimensions,
I find it convenient to place the valves in boxes as appearing in the
annexed Drawings.
4. The expanding cistern is expanded when required by water flowing
into it from the aquarium through the discharge pipe, as herein-after
shewn, and is compressed when required by weight or force applied, as
herein-after shewn, or in some similar manner.
follows:-
5. The action of the before-mentioned apparatus is as
Sunuese the aquarium 1. 1. Figure I., filled to the highest level required,

page_text: dotted lines 2, 2, herein distinguished as the high level, the expanding
tank 3, 3, placed below the aquarium and the upper side 4, 4, of such
expanding tank fixed, the lower side of such expanding tank having
been pressed by the weights 5, 5, placed on the shelf 6, 6, and by means
of the chains 7, 7, passing over pullies and pressing up the lower part
of the expanding tank to its highest position. Let the weights be
removed, the pressure on the lower side of the expanding tank will
immediately be diminished, the water will flow through the discharge
pipe 8 and through the valve 9-into the upper section 10 of the expand-
ing. tank 3, 3, and after percolating the filtering medium 11, 11, will
in a purified state enter the expanding section 12, 12, of the expanding
tank, and will stretch such expanding tank to its utmost capacity, and
the water in the aquarium will then have sunk to the low level 13, 13.
When it is required to return the water so purified into the aquarium,
the weights 5, 5, (which must in this case, assuming the lower side of
thie.expanding tank to be horizontal, be at least slightly greater than the
pressure of a column of water equal in height to the difference between
the level for the time being of the surface of the water in the aquarium
and the level of the lower side of the expanding tank acting on the
the whole of such lower side) will be again placed on the shelf 6, 6, and
such weights acting on the lower side of the expanding tank will com-
press such tank and force the water in a purified state back into the
aquarium through the supply pipe 14 and valve 15, until the water in
the aquarium again rises to the high level, the valve 9 allows the water
to pass through the discharge pipe from the aquarium into the expanding
tank, but prevents the water from returning into the aquarium through
such discharge pipe; on the other hand the valve 15 allows the water
to pass from the expanding tank into the aquarium, but prevents it
from flowing in the opposite direction through the supply pipe, the
process of partially discharging and refilling the aquarium may be
repeated in like manner whenever required.
6. For the purpose of emptying the aquarium if required I use a pipe
connected with its lowest part and furnished with a cock, and for the
purpose of emptying or cleansing the expanding tank I place both
above and below such expanding tank suitable pipes and cocks, as
shewn in Figure I. I also employ a pipe 16 furnished with cock 17,
for the purpose of connecting the section which is on one side of the
filtering medium with that which is on the other side of such medium,
so that if need arises the cock may be opened, and the water may be

page_text: assed from the section above the filtering medium into that below the
iltering medium without passing through such medium.
7. Figure II. represents a similar apparatus, with this difference, that
n Figure II. the lower side of the expanding tank is fixed, while the
upper side is moveable and the weights 5, 5, are placed when required
on such upper side; in this form of the apparatus the chains and pullies
are not required, but the discharge and supply pipes must be made
proportionably longer.
8. I find it is not required as erroneously stated in my Provisional
Specification to carry the top of the discharge pipe to the low level, and
that in fact such discharge pipe may conveniently commence from the
very lowest part of the aquarium, but I prefer carrying the supply pipe
at least as high as the low level so as to insure, as far as may be, the
purification in succession of the different portions of the water contained
in the aquarium.
I
9. When circumstances permit, for instance, when the aquarium is
placed in a lower storey in any house, and such house contains any
house water tank in an upper storey and therefore at some height above
the aquarium, it may be convenient to substitute instead of weights
acting on the expanding tank hydrostatic pressure.
10. For this purpose, assuming the upper side of the expanding tank
to be fixed and the lower side to be moveable, a small cylinder having
in it a piston similar to the piston used in a Bramah's press, and working
up and down may be fixed below the expanding section of the expanding
tank, such cylinder being connected either with the house water tank or
some small auxiliary water tank by a suitable pipe; such piston must
be capable of moving through space equal to that through which the lower
side of the expanding tank is required to move, and the size of the piston
must be regulated by the height of the column of water from the house
or auxiliary cistern to the cylinder, and if such height be considerable as
compared with the distance between the lower level of the expanding
tank, and the surface level of the water in the aquarium it. is obvious
that the size of the cylinder may be small in comparsion with the
volume of the water contained in the expanding part of the expanding
5 tank, and in that case the quantity of water required for working the
apparatus will be proportionately small.
11. The operation of such apparatus would be as follows:-Supposing
the expanding portion of the expanding tank to be at its lowest point

page_text: and the cylinder C, C, Figure III., to be empty suitable clockwork would
at the
proper timo open the cock C, and simultaneously close the cock C¹
and communication between the house or auxiliary cistern, and the
eylinder being opened the piston will by the pressure of the water in
the pipe p, be raised and will compress the expanding tank, and
thus cause the water therein to return to the aquarium. When this
has been effected, and the water in the aquarium has been raised to
the highest level, suitable clockwork would close the cock C and open
the cock C¹, the water in the cylinder C, C, would escape, and the
pressure of the piston on the lower side of the expanding tank would
be removed, and this being done, the water would again flow through
pipe 8 from the aquarium into the expanding tank, and that process
might be repeated whenever required. It is obvious that instead of
applying clockwork, cocks C and O might be opened and shut when
required by any person having the care of the aquarium.
12. Another form of carrying out the changes of level in an aquarium
would be to have two aquaria of similar capacity, exactly balanced and
suspended from a frame capable of rising and falling upon an axis in a
see-saw fashion. In this case each aquarium would be suspended from
the frame somewhat in the same manner as a compass is suspended in 2
a binnacle, the two aquaria must be connected by a flexible pipe, and
a weight can be placed on a rod connected with each aquarium by
another vertical rod and hinge, such weight being capable of being
moved along the first mentioned rod; such apparatus is represented in
Figures IV. and V.
2
13. In these Figures a, a, is the axis on which the frame is suspended,
A, A¹, the two aquaria; p, the flexible pipe connecting the two aquaria;
supposing the aquarium A elevated the aquarium A¹ being at the same
time depressed, then there being communication between the two
aquaria by means of the flexible pipe, the water in aquarium A will be 3
at the level of that in aquarium A¹ and consequently aquarium A will be
comparatively empty, whilst aquarium A' will be proportionately full; let
the weight P suspended from the rod V be moved from underneath the
aquarium A¹ along the rod V until it takes the position shewn in the
Figure by the red lines under aquarium A. This movement can readily 36
be effected by clockwork or by a windlass working into a rack attached
to the weight or into wheels carrying an endless chain attached to the
weight. In this case I find it the more convenient plan to have the

page_text: filtering medium in a distinct vessel through which the flexible pipe.
passes, and it may be convenient to have two flexible pipes, one with a
valve which allows the water to pass only from A to A', and the other
with a valve which allows the water to pass only from A¹ to A.
14. The weight must be of such force that when it is placed below
the partially empty aquarium A it will overbalance the more full
aquarium A', the aquarium A will then sink while aquarium A¹ rises,
and the water will flow from aquarium A' into aquarium A, until it
attains the same level in the two aquaria, the same process can be
repeated from time to time by shifting the weight P from underneath A
to underneath A', and from underneath A¹ to A alternately. Instead
of one of such two aquaria an auxiliary cistern might if so desired be
employed.
15. It is obvious that variations may be made in the details of the .
apparatus, so as to apply the Invention to aquaria of various sizes,
and to make the best use of the space and position which circumstances
may afford.
16. I claim for my Invention the withdrawing and returning water
from and to an aquarium, and purifying such water for such purpose,
in such manner and by such arrangements and apparatus as aforesaid,
but I do not claim the exclusive use of any of the parts of the apparatus
employed as aforesaid except in combination and for the purposes
aforesaid.
In witness whereof, the said Thomas William Kennard, hath here-
unto set his hand and scal, this Twenty-sixth day of September,
in the year of our Lord One thousand eight hundred and
seventy-three.
Signed, scaled, and delivered by
the above-named
Thomas
William Kennard in the
presence of
JOHN TURNER,
24, Lincoln's Inn Fields,
Solicitor.
T. W. KENNARD. (L.S.)