Means for Preventing Evaporation of Water in Reservoirs or the like.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Means for Preventing Evaporation of Water in Reservoirs or the like.
I, ROBERT MACNAIR WILSON SWAN, of 74, Bath Street, Glasgow, North Britain,
Mining Engineer, do hereby declare the nature of my invention to be as follows:--
In certain districts where the climatic, or atmospheric, influences are such as to
cause rapid evaporation, great loss of water occurs from natural, or artificial reser-
voirs, or other containers or places of storage, of water by the rapid evaporation of
water therefrom. In places where water is scarce this loss by evaporation is very
serious & it is the object of my invention to prevent such loss.
According to my invention I apply over the whole of the surface of the water,
contained in a natural or artificial reservoir or the like a covering or film of oil,
or oily matter, of a nature which will not readily evaporate, or become absorbed
by the water, or be oxidized, or have its protective character injured by climatic
or atmospheric, influences. A suitable oily matter consists of heavy mineral oil
such as the so-called waste of petroleum, or crude petroleum itself may be used
as any evaporation of the more volatile portion thereof which may occur will still
leave upon the surface of the water a covering or film of the less volatile con-
stituents.
I however do not limit myself to the use of the said products as I may use any
other oil, or mixture of oils, or oily matter possessing the requisite properties as
hereinbefore mentioned.
I will refer to the matter used as "oil" for the sake of brevity. The oil is
distributed over the entire surface of the water by any suitable means such for
example as by spraying it thereover either from the banks, or margin of the reser-
voir, or other container, or from a vessel floating on the surface of the water and
carrying a storage of the oil and a device by which it can be ejected and atomized
or sprayed onto the surface of the water; or I may distribute the oil from the wind-
ward side of the reservoir, or the like, so that the wind by carrying the oil to lee-
ward will assist in the distribution of the oil over the entire surface of the water.
In situations where the wind would be liable to drive the oil to leeward it may
tend to remove it from the windward portion of the reservoir or the like, so as to
leave that portion unprotected or only partially protected I prevent this by applying
to the surface of the water floating bodies, or bodies which are supported at suitable
intervals on the surface of the water such for example, as bars of wood, properly
anchored, or otherwise held in position, or nets of a suitable material such as
cocoa nut fibre or coir may be used or I may use mats or other fabrics of interwoven
fibre grasses reeds or the like and saturated with oil or such fabrics of a very loose
and open texture and on which the oil may be sprayed. If such nets or mats be
made of a material of a buoyant character they may be self supporting on the
surface of the water but if they be not of such character they may be supported
at intervals by floating bodies, or by stakes, or other means introduced and secured
in position, at suitable intervals or places.
Means will be provided by which the water can be drawn off from beneath the
oil, such for example as pipes which dip to beneath the surface through which pipes

page_text: the water can be pumped from beneath the surface, or by pipes or passages, passing
out at or near the bottom of the reservoir or by sumps or wells at the bottom of
the reservoir and the entrance to these pipes or passages may be protected by a
sand or other filter or strainer to guard against oil or other impurity, being drawn
off with the water.
{}
The application of a film, or covering, of oil to the water according to my inven-
tion efficiently protects the water from evaporation by climatic or atmospheric
influences as long as the water and the atmosphere are separated from contact with
each other by the interposition of the oil and the great loss of water which at present
results from that cause is prevented.
Dated this 17th day of July 1897
1
I, ROBERT MACNAIR WILSON SWAN, of 74, Bath Street, Glasgow, North Britain,
Mining Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described' 'and ascertained
in and by the following statement:-
"
1
In certain districts where the climatic or atmospheric influences are such as to
cause rapid evaporation,.great loss of water occurs from natural or artificial reser-
voirs or other containers or places of storage of water by the rapid evaporation of
water therefrom. In places where water is scarce this loss by, evaporation is very
serious and it is the object of my invention to prevent such loss.
According to my invention I apply. over the whole of the surface of the water,
contained in a natural or artificial reservoir or the like a covering or film, of oil,
or oily matter, of a nature which will not readily, evaporate, or become absorbed
by the water, or be oxidised, or have its protective character injured, by climatic,
or atmospheric, influences. A suitable oily matter consists of heavy mineral oil
such as the so-called waste of petroleum, or crude petroleum itself may. be used
as any evaporation of the more volatile portion thereof which may occur. will still
leave upon the surface of the water, a covering, .or film of the less. volatile con-
stituents.
...ul
I however do not limit myself to. the use of the said products.as. I may use any
other oil, or mixture of oils, or oily matter, possessing the requisite properties as
hereinbefore mentioned.
I will refer to the matter used as "oil" for the sake of brevity. The oil is
distributed over the entire surface of the water by any suitable means, such, for
example, as by spraying it thereover either from the banks, or margin of the reser-
voir, or other container, or from a vessel floating on the surface of the water, and
carrying a storage of the oil and a device by which it can be ejected, and atomized,
or sprayed, onto the surface of the water; or I may distribute the oil from the wind-
ward side of the reservoir, or the like, so that the wind:by carrying the oil to lee-
ward will assist in the distribution of the oil over the 'entire surface of the water.
In situations where the wind would be liable to drive the oil to leeward it may
tend to remove it from the windward portion of the reservoir, or the like, so as to
leave that portion unprotected or only partially protected. I prevent this by applying
to the surface of the water floating bodies, or bodies which are supported at suitable
intervals on the surface of the water, such, for example, as bars of wood, properly
anchored, or otherwise held in position, or nets of a suitable material such as
cocoa nut fibre or coir may be used, or may use mats or other fabrics of interwoven
Pie 20

page_text: fibre, grasses, reeds or the like and saturated with oil or such fabrics of a very loose
and open texture and on which the oil may be sprayed. If such nets or mats be
made of a material of a buoyant character they may be self supporting on the
surface of the water but if they be not of such character they may be supported
at intervals by floating bodies, or by stakes, or other means, introduced, and secured
in position, at suitable intervals, or places.
Means will be provided by which the water can be drawn off from beneath the
oil. such for example as pipes which dip to beneath the surface through which pipes
the water can be pumped from beneath the surface, or by pipes, or passages, passing
out at, or near, the bottom of the reservoir; or by sumps or wells at the bottom of
the reservoir and the entrance to these pipes, or passages, may be protected by a
sand, or other filter, or strainer, to guard against oil, or other impurity, being drawn
off with the water.
The application of a film, or covering, of oil to the water according to my inven-
tion efficiently protects the water from evaporation by climatic, or atmospheric
influences as long as the water and the atmosphere are separated from contact with
each other by the interposition of the oil and the great loss of water which at present
results from that cause is prevented.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I claim
is:-
1. The application to water contained in reservoirs, or the like, of a film, or
covering, of oil, or oily matter; substantially as, and for the purpose, hereinbefore
described.
2. The application to water contained in reservoirs, or the like, of a covering,
or film of oil, or oily matter, by spraying over the surface thereof the oil, or oily
matter, used; substantially as, and for the purpose, herein before described.
3. The application to water contained in reservoirs, or the like, of a covering or
film of oil, or oily matter, in combination with network, or matting or other form
of interwoven fibres, grasses, reeds or the like, or other floating bodies or nets, or
bodies, supported at the surface of the water, to prevent displacement of the cover-
ing, of oil or film, or oily matter; substantially as, and for the purpose, herein-
before described.
4. The application to water contained in reservoirs, or the like, of a covering,
or film of oil, or oily matter, in combination with a network, or other floating bodies,
or nets, or bodies, supported at the surface of the water, and means for drawing off
water from beneath the said covering or film; substantially as, and for the purposes,
hereinbefore described.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.