CERTAIN IMPROVEMENTS IN APPARATUS FOR MANUFACTURING SALT
Year: 1846

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
ELLINS, of Droitwich, in the County of Worcester, Salt Manufacturer, send
greeting.
WHEREAS I did, by Petition, humbly represent unto Her most Excellent
Majesty Queen Victoria, that I had invented "CERTAIN IMPROVEMENTS IN
APPARATUS FOR MANUFACTURING SALT," and Her said Majesty being willing to
give encouragement to all arts and inventions that may be for the public
good was graciously pleased, by Her Royal Letters Patent, under the Great
Seal of the United Kingdom of Great Britain and Ireland, bearing date at
Westminster, the First day of December (One thousand eight hundred and
forty-six), in the tenth year of Her reign, for Herself, Her heirs and
successors, to give and grant unto me, the said George Ellins, my executors,
administrators, and assigns, Her especial licence, full power, sole privilege
and authority, that I or they, by myself or themselves, or by my or their
deputies, servants or agents, or such others as I or they should agree with,
and no others, during the term of fourteen years from the date of the
said Letters Patent, should and lawfully might make, use, exercise, and vend
my said Invention, within that part of Her said Majestie's Dominions called
England, Her Dominion of Wales, and Town of Berwick-upon-Tweed, in such
manner as to me, my executors, administrators, and assigns, shall seem meet; and
ps that I or they shall enjoy the whole profit and advantage arising by reason
of the said Invention during the said term of fourteen years. And whereas

page_text: the said Letters Patent contain a proviso obliging me, the said George Ellins,
particularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, by an instrument in writing under
my hand and seal, and to cause the same to be enrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said Letters Patent, as in and by the same, reference
being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
George Ellins, do hereby declare that my said Invention is described and
ascertained in manner following, and by the aid of the Sheet of Drawing
hereunto annexed, that is to say:—
That part of my said Improvements in Apparatus for Manufacturing Salt is
to apply metal pipes within the salt pan or vessel, wherein salt brine is to bo
heated and water evaporated therefrom, so as to cause salt to crystalize and
separate itself from the said brine; such metal pipes being disposed in rows
within the pan, so as to be immersed in and surrounded by the brine, and
being kept supplied with steam or with hot water, passing in a continued
current through the interiors of such pipes, for the purpose of communicating
heat through the metal whereof the pipes are composed, from the steam or
hot water which is within their interiors to the brine by which they are
surrounded exteriorly; the disposition of the said pipes within the pan being
such as will leave suitable spaces between the rows of pipes for raking or
gathering the salt towards the side or sides of the pan, and then taking it
up out of the pan.
Figure 1 of the Drawing hereunto annexed is a horizontal plan; and
Figure 2 a corresponding longitudinal vertical section of a salt pan or vessel
as aforesaid, constructed according to this part of my improvements. Figure 8
is a transverse vertical section. The same letters of reference are used to
denote the same parts in all the Figures. a, a, Figure 3, is the flat bottom;
and b, b, the sides of the salt pan, made of iron plates rivetted together in the
usual manner of making salt pans. A, A, is the flat bottom; and B, B, the
upright sides of a lower vessel or case, made of wood, within which vessel the
iron pan b, a, a, b, is placed; and the upper edges of the iron sides b, b, and
of the wooden sides B, B, are closely joined together by screw bolts at e, e
so that the space between the two bottoms a, a, and A, A, will be an enclosed
space capable of retaining steam or hot water (or both), within it; and the
heat from such steam or hot water will be transmitted upwards through the
iron bottom a, a, so as to communicate heat to the brine resting thereon.
The lower bottom A, A, and exterior sides B, B, on account of the slow con-

page_text: ducting nature of wood, will retain the heat of the steam or hot water, and
prevent waste of the heat. 1, 2, 3, 4, 5, &c. to 20, are the metal pipes, dis-
posed with their lengthway nearly (but not quite) horizontally, and in a
direction across the width of the pan, as shewn in the Plan, Figure 1. The
pipes marked with odd numbers 1, 3, 5, 7, &c. are so many straight lengths
of pipe, with a flange (or other suitable kind of joint) at each end of each
length, by means whereof they are united to like flanges (or corresponding
joints) at the ends of the curved pipes marked with even numbers 2, 4, 6, 8,
&c., so as by the union of the straight and the curved pipes to form a long con-
tinuation of piping, which extends in a zigzag course throughout the pan, the
said piping being near to the iron bottom a, a, and wholly immersed beneath
the brine which is resting on that bottom. The said piping is connected with
the iron bottom a, a, at each end y and z of the long zigzag course, by these
two ends bending down with flanges to join to the bottom a, a, and thereby
forming an open communication between the interior of the piping and the
space between the two bottoms a, a, and A, A, for permitting the steam or hot
water contained in that space to enter freely into the interior of the piping,
which piping must also be connected with the bottom a, a, at convenient inter-
mediate places in the length of the long zigzag course between the two
ends y and thereof; for instance, at s and n and r, each such intermediate
connection being made by a flange at the lower end of a turn-down branch
from the middle of one of the curved pieces, as at 10, 20, and 80, n. The said
connections at n and are for permitting water to pass out from the interior
of the piping into a pipe w, Figure 3, which extends along within the space
between the bottoms a, a, A. A, and which pipe serves to convey away water
from as many of the connections, such as n and, as there may be. The
other connections at y and z and s being (as already mentioned) for permitting
steam or hot water to enter into the interior of the piping. The Plan,
Figure 1, only represents the piping in a short length of pan, which short
length may be considered as one half. or portion of a long pan, wherein the
piping continues its zigzag course throughout the whole extent of the pan,
as shewn by the dotted lines; and the connections, such as y and z and s, for
entrance of steam or hot water into the piping (as well as being at those two ends),
should be also at s, or at as many intermediate places between those ends y and z
as may be judged expedient, in order to divide the whole length of the zigzag
course of piping into suitable portions for completely supplying the interior of
the piping with steam or hot water through its several entrance connections with
the space between the two bottoms a, a, A, A, and wherever such entrance con-
nections as y and z and s may be in the zigzag course of piping, the other or
exit connections (such as n and a) should be at intermediate places in the zigzag

page_text: course between the said entrance connections y and z and s, because the steam or
hot water which is to make its entrance into the interior of the piping at each of
the entrance connections such as y and z and s, will proceed therefrom along the
zigzag course of the piping to the nearest of the exit connections n or x, where
water will pass out (as already mentioned) into the pipe w. For in case of the
interior of the piping being kept supplied with steam, part of that steam in
communicating heat through the metal of the piping to the surrounding brine
will be condensed into hot water, which hot water will collect at the lower part of
the interior circumference of the piping, and pass along the zigzag course thereof
to the nearest exit connection such as n or ac, where it will descend into the
pipe w, and be conveyed away; but that pipe being full of water will not convey
steam away. And in order to facilitate the said passing of condensed water
along the interior of the piping in a direction towards the nearest exit connec-
tion the piping should be lower at all those exit connections such as n and x,
and higher at all the entrance connections such as y and z and s, in order that
the pipes (although nearly horizontal) may not be quite level, but may have
such an inclination from a true level as will cause the condensed water to
run along the zigzag course of the piping to the nearest exit communication.
The arrangement of the piping shewn in the Plan, Figure 1, will permit the
salt which has been deposited from the brine to be raked away from the
middle part of the pan towards the sides thereof, because the straight pipes 3
and 5, 7 and 9, 11 and 18, &c., are disposed at sufficient distances asunder
for a rake or scraper to act between them without inconvenience, and the
rake will pass beneath the pipes so as to act all over the bottom a, a, of the
pan without interruption, except at the few places of the entrance and exit
connections y, z, and s, and n and x aforesaid, those being the only places
where the piping has any connection with the pan. The straight pipes 1 and
3, 5 and 7, 9 and 11, 18 and 15, &c., are as near together as their flango
joints will permit them to be placed with convenience, because it is not
intended to work a rake between them. The curved pipes 4 and 8 approach
within a few inches of the side D, Figure 1, of the pan, but the other curved
pipes 2, 6, 10, and 14, do not approach so near to the other side E of the
pan, in order that there may be a sufficient space left clear along that side E
for taking out the salt after it has been raked over to that side E, without any
interruption from the pipes. And this part of my improvements in apparatus
for manufacturing salt may be used in different ways, and either with steam or
with hot water, or both, as may be judged most suitable by the manufacturer.
The space between the two bottoms a, a, and A, A, may be kept supplied with
steam from any suitable kind of steam boiler, a steam pipe from that boiler

page_text: being connected with any part of the lower bottom A, A, or the sides B, B,
so as to introduce an ample supply of steam into the said space; and if the
pan is of very large size it may have two or more such steam pipes as afore-
said connected with the said space, at different places far.asunder, for more
complete supplying of the said space with steam. And the said two or more
steam pipes may be branches of a steam pipe proceeding from one steam boiler,
or they may be steam pipes proceeding from distinct steam boilers, the said
steam boiler or boilers being in any case provided with proper safety valves
and with suitable apparatus for indicating the quantity of water in the boiler
and for regulating that quantity, the same as in ordinary steam boilers, and
which being well known need not be further described. And the said space
between the bottoms a, a, and A, A, must be also provided with safety, pipes,
joining to the sides B, B, Figure 2, and turning upwards with valves applied
on their upper ends; those valves, being unconfined except by their own weight,
will act as very lightly loaded safety valves to allow the steam to escape when-
ever its elastic force is a little greater than the pressure of the atmospheric
air. The said safety pipes should join to the sides B, B, at the highest parts
of the space between the two bottoms a, a, and A, A, in order that when the
apparatus is first set to work and steam or hot water is supplied to fill the said
space as aforesaid, that all air may be able to make its escape from the said
space between the two bottoms through the said safety pipes, the valves thereof
being lifted up for that purpose, and thereby the said space will become com-
pletely filled with steam or hot water, without allowing any air to be confined
therein. Also one or more reversed valves may be provided at the upper
parts of some of the said safety pipes, by way of security against accident;
such reversed valves opening inwards into the pipes to which they are applied,
in order that they may admit atmospheric air into the space between the two
bottoms a, a, and A, A, when the steam therein is allowed to cool and con-
dense, in which case it would leave the said space exhausted unless the atmo-
spheric air is allowed to enter, but if prevented from entering its pressure would
cause the bottom. A, A, or a, a, to collapse. If the safety valves are lifted up
and kept open, or are removed from the upper ends of the safety pipes, then
the air would have free admission as the apparatus cools. The reversed valves
are only for precaution against the consequence of neglecting to keep open the
valves. Such reversed valves are. most commonly applied to ordinary steam
boilers, and are well known. If there are reversed valves on the boiler or
boilers from which steam is to be supplied to the space between the two
bottoms a, a, A, A, those reversed valves on the boilers would be sure to admit
air when required, provided there are no stop.valves in the steam pipe or pipes

page_text: which communicate between the boiler or boilers and the said space between
the two bottoms; and in order to give strength to the two bottoms A, A, and
.a, a, they are to be connected together by upright stays which may be applied
in a similar manner to the internal stays within steam boilers, the said
stays to be applied at such distances one from another, and so distributed
over the whole area of the two bottoms a, a, and A, A, as to connect
those two bottoms effectually together, and thereby cause any downward
pressure of steam or hot water on the bottom A, A, to be fully coun-
teracted by the corresponding upward pressure beneath the bottom a, a. The
steam which ascends from the space between the two bottoms a, a, A, A, into
the zigzag piping at the several entrance connections y and s and s, will operate
within the piping to communicate heat through the middle of the piping
to the brine by which the piping is surrounded, as already stated, and the
heat so communicated to the brine will be in addition to all the heat
that is communicated thereto by transmission of heat upwards through the
-bottom a, a, in manner already stated; and by such twofold communication
of heat to the brine its evaporation and the formation of salt from it is
.accelerated. Nevertheless it is not essential to this first part of my im-
.provements that there should be such a twofold communication of heat to the
brine, for the piping may be used as the only means of communicating heat
without having any space between two bottoms, such as a, a, and A, A; and it
will, in such case, be unnecessary to have more than one bottom, which one
.bottom may be either the iron bottom a, a, with its sides b, b, constituting
an iron salt pan, to be heated by means of piping immersed in the brine
contained in such iron pan, or may be the wooden bottom A, A, with its sides
.B, B, constituting a wooden salt pan, heated by means of piping immersed in the
brine contained in such wooden pan. In either such case, steam or hot
-water may be supplied to the interior of the piping from a supply pipe passing
horizontally beneath the one bottom of the salt pan (whether that bottom be
'iron or wood), and joining by suitable upright branches with the several
entrance connections into the piping, such as at y, z, and s, already explained.
The dotted lines at p, Figure 8, represents the place of such a supply pipe, which,
as to its position beneath the bottom of the salt pan and its mode of junction
with the said entrance connections y, z, and s, will be very similar to the
position of the pipe in Figure 3 (for conveying away water as already
mentioned), and similar to the junctions of the branches of that pipe w with the
several exit connections n and x. The said supply pipe p will be part of the
steam pipe or pipes coming from the boiler or boilers as before mentioned; but
instead of being connected with the lower bottom A, A, or exterior sides B, B,

page_text: as before mentioned, the said steam pipe or pipes must be prolonged and
disposed horizontally as at p, to join by ascending branches to the several
entrance connections y, z, and a. The water resulting from condensation of
steam within the piping will run as already mentioned to the nearest exit
connection, n or a, and pass thereby into the pipe w, which pipe, with suitable
prolongation thereof, will convey the said water or condensed steam to the
boiler or boilers for the replenishing thereof with water, the boiler or
boilers, being situated at a level so much lower than the pipe w, Figure 3, as
to ensure that such passage of the water into the boiler shall take place.
And whereas piping of iron will sustain a strong pressure of steam within its
interior without danger of bursting, the steam which is supplied through the
pipe p to the interior of the piping may be high-pressure steam, coming from
a suitable high-pressure steam boiler, which is provided with proper safety
valves, and all the appertenances as usual in the boilers of high-pressure
steam engines; and inasmuch as that the temperature of steam is
higher than boiling (or two hundred and twelves degrees), when its elastic
pressure is greater than the ordinary atmospheric pressure, so the high-
pressure steam which may be supplied to the piping will communicate a
higher temperature to the brine by which the piping is surrounded than
the same piping could communicate if it were supplied with steam of the
ordinary atmospheric pressure; and high-pressure steam may be so supplied
as aforesaid to the interior of the piping by means of a supply pipe, such
as p, even when the apparatus is constructed in all other respects (except
as to the addition of that supply pipe p) as herein-before described and repre-
sented in Figure 3, with a space between two bottoms, a, a, and A, A; and
when that space is kept supplied (in manner already explained) with steam,
whereof the elastic force is only a little greater than the pressure of the
atmospheric air, the supply of such steam as last mentioned to the said space
being derived through suitable pipes from a boiler or boilers, which is or are
distinct from the aforesaid high-pressure boiler, from which the interior of the
piping is kept supplied with high-pressure steam by means of a supply pipe,
such as p; wherefore in the case now describing there will be a twofald
communication of heat to the brine, as already mentioned, but with the
difference that the heat which is communicated to the brine by transmission
upwards from the space between the two bottoms will be derived from a source
which is distinct from the source of the heat which is communicated by
transmission through the metal of the piping from the high-pressure steam
within the interior of that piping, and which latter transmission may
operate safely with a higher temperature than the other upward transmission

page_text: can do, without danger of bursting the apparatus; and although it has been
described as if the space between the two bottoms a, a, and A, A, is to be
: supplied with steam from a boiler or boilers, that is not an essential condition,
except in case of the lower bottom A, A, and the exterior sides B, B, being
made of wood; for if the same bottom and sides A, A, B, B, are made of iron
plates rivetted together in the usual manner of making salt pans, then the heat
of fire may be applied beneath the said lower iron bottom A, A, to communicate
heat by an upward transmission from such fire through that bottom to water
contained in the space between the two bottoms a, a, and A, A (that water
resting on the lower iron bottom A, A), so as to cause that water to boil and
raise steam, which will occupy the upper part of the space between the two
bottoms; and such steam will operate beneath the upper bottom a, a, to give
hent to the brine above it, in the same manner as already explained respecting
'steam to be supplied from a steam boiler or boilers to the space between the
two bottoms. The said space in the case now describing operating instead of
a steam boiler, as well as operating in the manner of a steam casing beneath
the upper bottom a, a; and part of the steam só produced within the
space between the two bottoms by action of fire heat beneath the lowermost of
'those two bottoms may enter into the interior of the piping for supplying the
same with steam, or otherwise the said interior may be supplied, by means of
the pipe p, with high-pressure steam from a suitable boiler, as already
explained. The lower iron bottom A, A, may either have a direct application
of fire heat beneath it, in which case it will be set over a furnace or furnaces,
wherein fuel is burned in the usual manner of ordinary salt pans; or otherwise
the said lower iron bottom A, A, may have only the secondary heat
proceeding through flues from the fires in a furnace or furnaces beneath an
ordinary salt pan aforesaid, in which case the lower iron bottom A, A,
will be set over flues beyond such ordinary salt pan, in the usual
manner of what is termed a back pan or second pan, situated beyond
or behind an ordinary salt pan, and heated by the secondary heat
proceeding through flues from the fires beneath the first or principal pan. And
note, whereas it has been mentioned that steam or hot water, or both, may be
applied within the space between the two bottoms a, a, A, A, the application
of steam therein has been explained; and also of the application of both hot
water and steam in the case when fire heat is applied beneath the lowermost
bottom A, A; and the said space is made to serve instead of a steam boiler
as well as to serve for a steam casing beneath the upper bottom a, a.
In such
case the quantity of the water on the lower bottom A, A, must be kept up in
"the same manner as in any other steam boiler, to avoid boiling dry; but as

page_text: fast as steam is condensed into water when acting beneath the upper bottom a, a,
that water will descend again to mix with the water beneath to be again
converted into steam, so that the waste of water will be only by the escape of
steam at the safety valves, which will not be great, and a small supply will
keep up the quantity. That supply is to be made when required in the
usual manner of supplying a steam boiler with water; and in the case of the
space between the two bottoms being supplied with steam from a steam boiler
or boilers, as already explained, as fast as steam is condensed into water
by acting beneath the upper bottom a, a, that water will fall down
upon the lower bottom A, A, and as it collects on that bottom should
be conveyed away by suitable pipes for replenishing the steam boiler with
water in the same manner as already mentioned respecting conveying
away water from the pipe w; and in case of the interior of the piping being
supplied with steam from the space between the two bottoms, then the said
suitable pipes and the prolongation of the water pipe w may go together to
the boiler, or one pipe may serve both to carry back to the boiler the water
condensed within the piping as well as the water condensed beneath the upper
bottom a, a; in case of the piping being supplied with bigh-pressure steam, then
the prolongation of the water pipe w must carry back the water condensed
within the piping to the high-pressure boiler, the other pipe carrying back to
the other boiler the water condensed beneath the upper bottom a, a. And
respecting the application of hot water within the space between the two
bottoms instead of steam therein, the same will not require much difference of
explanation beyond what has been already stated. If the whole space is filled
with water and fire heat is applied beneath the lower bottom A, A, then to allow
for expansion and contraction of such water a pipe or pipes may be joined
to any convenient place or places at the lowest part of the sides B, B, to ascend
therefrom, and connect the said space with a cistern or cisterns, which, being
open (or loosely covered), will receive so much water out of the said space
as may be requisite to allow for expansion, and will allow as much water to
return when contraction takes places. And the same safety valves already
mentioned as being provided for the escape of surplus steam (whenever. the
elastic force thereof becomes a little greater than the atmospheric air) will, in the
present case, allow any steam to escape which may arise from the hot water;
and the load on those safety valves must be regulated to suit the height of the
aforesaid water cistern or cisterns, so that the valves will open before the
water is forced up in the cistern above the upper edge thereof so as to over-
flow. Or, instead of applying fire heat directly beneath the lowermost bottom
A, A, the space between the two bottoms may be kept constantly supplied with

page_text: hot water by circulation thereof through a distinct hot-water boiler, which is
set over a suitable furnace, so as to be heated by fire in order to heat the
water contained in the boiler, which must be connected with the space between
the two bottoms by two hot-water pipes, one proceeding from the uppermost
part of the boiler to the nearest end of the said space in order to introduce
hot water into that end, and the other pipe returning from the farthest end
of the said space to the lowermost part of the boiler, for the purpose of con-
veying back the water after it has become somewhat cooled by the communi-
cation of part of its heat through the metal of the uppermost bottom to the
brine above that bottom. Wherefore the water will perform a continual cir-
culation through the boiler and through the space between the two bottoms,
the water receiving heat when it is in the boiler, and giving out part of that
heat when it is in the said space. And if the said hot water boiler is situated
at a lower level than the salt pan, then the said circulation of the hot water
will take place more effectually. The disposition of the piping within the appa-
ratus may be varied from what has been herein-before described in reference
to Figs. 1, 2, and 8; and the same effect will be produced as already stated,
see Fig. 4, which is a horizontal plan, and Fig. 5 a longitudinal vertical section
of a salt pan constructed according to this part of my improvements, with
piping immersed in the brine. Fig. 6 is a transverse vertical section on
a larger scale. Instead of pipes being arranged in a continuous zigzag.
course of pipes side by side near to the surface of the brine, and ex-
tending throughout the whole extent of the pan, the pipes are disposed side
by side, at suitable intervals apart, across the width of the pan from near one
side to near the other side thereof, and near to the surface of the brine; and
then from the end of each such pipe another pipe returns beneath it
at a lower level, and near to the bottom of the pan; the other two ends
of the said two pipes are joined to branches of an entrance and an exit pipe,
both of which extend horizontally along the same side of the pan. G, Fig. 6,
is the section of the horizontal entrance pipe, and II the section of the
horizontal exit pipe placed close beneath G. They are both flat pipes, of a
rectangular section, and when one is placed above the other within the pan,
and close to one side thereof, the two completely line that side of the pan
all the depth thereof, so that the brine comes in contact with the external
upright sides of both pipes G and H. Each pipe G and H, has a number of
branches projecting out from it with flanges or other suitable means of connec-
ting to flanges (or other corresponding means) at the ends of the straight pipes
I and K, the other ends of which are united together by a curved pipe h; steam
Is supplied to the entrance pipe G at its ends, or at any convenient part of its

page_text: length by a steam pipe or pipes from the high-pressure or other steam boiler
joining to the branches i, and the steam passing along all the length of the
entrance pipe G has free admission from that pipe at different places in its
length to the interiors of all the several pipes I, K, and the water resulting from
the steam that is condensed in them descends in consequence of a slight inclina-
tion that is given to each pipe I and K, and that water passes into the exit
pipe II, and proceeding horizontally along the length thereof passes away by a
descending pipel to return to the boiler for replenishing the same. The intervals
laterally between the several pipes I, I, (see Fig. 4) is sufficient for raking the
salt along the bottom of the pan to the side E thereof, and the curved pipes h
do not approach so close to that side as to be in the way of the workman when
he is taking the salt up out of the pan from that side E thereof. Fig. 7 is a
transverse vertical section of another salt pan corresponding to Fig. 6; but
Fig. 7 shews another mode of disposing the piping with three straight pipes
I, L. and K, one above another, the uppermost, I, being near to the surface
of the brine, and the lowermost, K, being near to the bottom of the pan,
the middle pipe, L, being intermediate between the two. The entrance
pipe G is a broad flat pipe, placed edgeway up at one side of the pan so as to
form a lining to the whole depth of the pan at that side, and the entrance
pipe G has branches to join to the upper pipes I, as already explained in
respect to Fig. 6. The end of the upper pipe I is joined to the end of the
middle pipe L with a curved pipe h, and the other end of L is joined by
another curved pipe k to one end of the lower pipe K, and the other end of K
is joined to the exit pipe H, which is situated at the opposite side of the pan,
and laid flat along the bottom thereof; and the boxes or moulds into which the
salt is to be filled when fine salt is made, can be placed upon the flat exit
pipe H. The supply of steam to the entrance pipe G, and the carrying away of
condensed water from the exit pipe II is the same as already explained in
respect to Fig. 6. The three pipes I, L, K, Fig. 7, expose an extensive
heating surface to the brine by which they are surrounded; but those three
pipes being one above another they require the brine to stand at a greater
depth in the pan Fig. 7 than is required in a pan with two pipes I, K, Fig. 6,
which are also one above another, and Fig. 6 requires the brine to stand
deeper in the pan than is required in a pan with the zigzag arrangement of
piping Fig. 3, in which the pipes are not one above another, but are all as
nearly at one height in the pan as is consistent with giving every part of the
zigzag piping so much inclination from a true level as to ensure an efficient
draining away of water, by descending from each entrance connection y, z,
and (which are the highest places in the zigzag course), to the nearest exit

page_text: .connection nor
(which are the lowest places in the zigzag course). The
pipes in Fig. 3 permit the salt which collects on the bottom of the pan to be
raked away from beneath them with more facility than the pipes in Figs. 6
or 7 will permit, because the lower pipes K, Figs. 6 and 7, must be nearer to
the bottom of the pan than any of the pipes in Fig. 8 require to be. And
note, in either of the arrangements, Figs. 6 or 7, the entrance and exit
pipes G and H being wholly within the pan above the bottom a, a, thereof, it
is not necessary that there should be any casing such as A, A, B, B, beneath
the bottom a, a, of the pan, but the whole of the heat may be communicated
to the brine from the piping without any sort of application of heat beneath
the bottom a, a, of the pan, which bottom, as well as the sides b, b, may in
such case be made of wood in the same manner as the bottom A, A, and
sides B, B (but without any iron bottom a, a, and sides b, b), the brine coming
in contact with and being retained by the wood B, A, A, B. Fig. 8, is
another transverse vertical section corresponding to Figs. 3, 6, and 7; but
Fig. 8 shews another mode of arranging the entrance and exit connections
for pipes which are disposed one above another in the brine, as in Figs. 6 or 7.
In Fig. 8 the horizontal entrance pipe G and the horizontal exit pipe H arc
disposed beneath the bottom a, a, of the pan in the space between the two
bottoms a, a, and A, A, in a similar manner to what has been already
explained in reference to Fig. 8, respecting the supply pipe, shewn by dotted
lines p and the return water pipe w. The horizontal entrance pipe G, Fig. 8,
has branches ascending from its upper side at such intervals apart along its
length as will suit the intervals between the pipes I, K, in the pan above, and
the upper end of each such branch joins to the lower end of a short upright
pipe q, which stands up from the bottom a, a, of the pan within the brine; and
the upper end of q is curved so as to assume a nearly horizontal direction
suitably for joining to one end of the straight pipe I, the other end of which is
joined by a curved pipe h to the corresponding end of the other straight pipe K,
which is beneath I, and the other end of the pipe K is joined to the short curved
pipe m, which descends to the bottom a, a, of the pan, and joins to a branch
at the upper side of the exit pipe H, beneath the bottom a, a, steam, being
applied from a high-pressure or other boiler to the entrance pipe G, at one or
both its ends, where it comes out from the space between the two bottoms a, a,
and A, A; that steam will ascend at g, and pass into the pipes I, h, K, so as to
keep the interiors thereof supplied with steam, and the water resulting from as
much of that steam as is condensed in those pipes will run down within them
towards m and H, in consequence of slight inclinations of the pipes I and K
from a true level, and the water which thus collects in the pipe II will run

page_text: along the same to be conveyed through other suitable water pipes to the boiler
for replenishing the same. And note, in Fig. 8, there may be, if preferred,
three straight pipes, one above the other, the same as I, L, K, in Fig. ?,
instead of only two, I, K, as in Fig. 8, which, in case of having an intermediate
pipe, such as L, would then have its exit pipe H and short curved pipe m
disposed beneath the contrary side of the pan to that side thereof beneath
which the entrance pipe G is disposed. And note, the entrance pipe G will
be unnecessary in case the pipes in Fig. 8 are to be supplied with steam from
the space between the two bottoms a, a, and A, A; and whether the steam is
supplied to that space by pipes from a steam boiler, or whether the steam is
generated within that space by fire heat (either direct or secondary) applied
beneath the lower bottom A, A (that bottom then being iron), in either way of
supplying the space between the two bottoms with steam, part of that steam
may ascend from the said space into the pipe q, and thence to the pipes I, h,.
K, and m, so as to supply the interiors of those pipes without requiring any
entrance pipe, such as G. And the exit pipe H may also be dispensed with if
each of the curve pipes m, after passing down through the bottom a, a, were
to descend in the space between the two bottoms, nearly or quite down to the
lower bottom A, A, and there turn up again a little way, with an open end,
like an inverted syphon drain pipe, then the water could run out freely at the
said open end of the turned-up pipe, and would mix with any water that
there might be on the lower bottom, which might either be water for the
purpose of generating steam for that water by fire heat (direct or secondary)
applied beneath the lower iron bottom A, A, or it might be water collected on the
lower bottom A, A, from condensation of steam beneath the upper bottom a, a,
in case of steam being supplied to the space between the two bottoms a, a, and
A, A, from a steam boiler, and in the latter case the water so collecting on the
lower bottom A, A, from the said condensation, and from the said open ends of
inverted syphon drain pipes, must be conveyed by a suitable return water pipe
or pipes to the said boiler for replenishing the same with water.
And note,
all that has been last stated respecting such inverted syphon drain pipes, will
equally apply to Fig. 3, in case of the piping thereof being supplied with
steam from the space between the two bottoms a, a, and A, A; for the water
pipe w, in Fig. 3, may be dispensed with if the exit connections n and of
the zigzag piping, with the bottom a, a, are provided with inverted syphon
drain pipes descending in the space between the two bottoms a, a, A, A,
nearly or quite down to the lowest bottom A, A, and there turning up with
open ends for allowing water to run out freely; but there will be so much
water retained in the said inverted syphon drain pipes as will prevent any.

page_text: entrance of steam through the exit connections. Fig. 9 is another transverse
vertical section, corresponding to Figures 3, 6, 7, and 8, but Fig. 9 shews
another mode of applying pipes. a, a, is the bottom, and b, b, the sides of
the iron salt pan, wherein the brine is contained, and A, A, is the bottom, and
B, B, the sides of the wooden vessel or steam case, wherein the pan is placed,
leaving a space between the two bottoms a, a, A, A, for steam, all as before
described respecting the other Figures 3, 6, 7, and 8, except that in Figure 9
the wood at the upper parts e, e, of the sides B, B, where the iron b, b, is joined
to the wood, is represented to be thicker than the other parts B, B, and A, A,
and thereby a space is left for steam all round the sides b, b, of the pan, which
sides are upright. And note, in the previous Figures 3, 6, 7, and 8, the wood
and iron sides may, if preferred, be constructed in the same manner as B, e, b,
Figure 9. The entrance pipe G, for steam, is carried horizontally beneath the
bottom a, a, and the short upright pipe 9 ascends from the upper side of the pipe G,
and the flange at the upper end of q joins to a flange at one end of the straight
pipe I, the other end of which is somewhat lowest and joins to a flange at the
upper end of the curved pipe m, which descends to the upper side of the exit pipe
H, disposed horizontally beneath the bottom a, a. The operation of Figure 9 is
the same as already explained in reference to Figure 8, except as to there
being only one long straight pipe in Figure 9, and also that the exit pipe H
is beneath the contrary side of the pan to that side thereof beneath which the
entrance pipe G is situated, the same as already mentioned would be the case
in Figure 8 if it had three long straight pipes instead of two. The entrance
and exit pipes G and H, Figure 9, may be cast-iron pipes of a rectangular
ection and flat at their upper sides, which upper sides may form part of
he bottom a, a, of the pan, if the iron plates of that bottom a, a, and of the
sides b, b, are rivetted to border flanges projecting from the edges of the
pipes G and H. In such case the brine will rest upon the upper sides of the
pipes G and H, and the steam within those pipes will communicate heat to
the brine. The said upper sides of the two pipes G and H have branches
standing upwards from them to join to the pipes I. And note, three pipes,
such as I, L, K, Figure 7, may be applied in Figure 9, instead of only one
pipe I. The entrance and exit pipes G and H may extend in manner aforesaid
all the length of the pan, having branches at suitable intervals apart along their
upper sides for joining to the several pipes I, which must be situated at such dis-
tances apart laterally as to permit of raking the salt along the bottom of the pan
in the said intervals between the pipes; and at any convenient place or places in
the lengths of the entrance and exit pipes G and H suitable conveyance pipes
are to be joined to them; viz., to the entrance pipe G a conveyance pipe or

page_text: sure.
pipes to bring steam from the high-pressure or other steam boiler for supplying
the interior of the pipe G, and to the exit pipe H a suitable descending drain
pipe or pipes to return condensed water from the interior of H to the boiler for
replenishing the same. And it has been already stated, that at the same time
the space between the two bottoms a, a, and A, A, is kept supplied with steam
of little more than atmospheric pressure, that the interior of the piping (in
any of the arrangements, Figures 3, 6, 7, 8, or 9) may be kept supplied with
high-pressure steam, in order thereby to communicáte more heat to, and keep
up a higher temperature in the brine, than could be done by supplying the
interior of the same piping with steam of little more than atmospheric pres-
And it has also been stated that the supply of steam of little more
than atmospheric pressure is to be derived from a boiler or boilers distinct
from the high-pressure boiler or boilers from which the interior of the
piping is supplied with high-pressure steam. Nevertheless, if preferred, a
portion of the high-pressure steam which is supplied to the interior of the
piping as aforesaid, may be let out therefrom through suitable loaded safety
valves, so as to become reduced in its elastic pressure suitably for supplying the
space between the two bottoms a, a, A, A. Such loaded safety valves will
operate as escape valves for the high-pressure steam, and they may be applied*
to branches of the exit pipe H, those valves being within the space between
the two bottoms a, a, A, A, so that all the steam which may make its escape
from the pipe H by lifting those valves will be received into the space between
the two bottoms, but will not keep up any greater pressure of steam therein
than is according to the weight on the safety valves, wherewith the said
space is provided, and which valves, as already explained, being uncon-
fined, except by their own weight, they will act as very lightly loaded
safety valves, to allow all surplus steam to escape, and prevent any acen-
mulation thereof within the space between the two bottoms beyond a
pressure a little greater than atmospheric pressure; or in case of a steam
engine being required for pumping brine or other purpose, if a high-pres.
sure steam engine is used, it may be worked with high-pressure steam from the
same high-pressure boiler as the interior of the piping is supplied from, and
the waste steam discharged from the engine may be conveyed by a continua-
tion of its waste steam pipe or eduction pipe to the space between the two
bottoms a, a, A, A, for supplying or partly supplying the same with steam
only a little stronger than atmospheric air. The manner of putting the pipes
together and forming the joints for them may be varied and may be left to the
skill and discretion of the workman who is to construct the apparatus. The
pipes may be cast-iron, and the joints, flanges; united by screw bolts and nuts,

page_text: rings of india-rubber packing being interposed between the meeting ends of
the pipes, and strongly compressed by screwing the nuts; or the long straight
pipes may be wrought-iron welded tubes, such as are now commonly
used for the tubular flues in the boilers for marine steam engines and
suitable flanges may be formed at the ends of such wrought-iron tubes by
running melted cast iron around tho said ends when they are laid
in suitable moulds formed in sand, in the manner well known to iron
founders, so as to form a flange of cast iron firmly united at the end
of the tube of wrought iron, and so of the curved pipes which are
to join to the ends of the long straight pipes (such as 2, 4, &c., Fig. 1,
or h and k, Fig. 7, or q and m, Fig. 8). Such curved pipes may be
cast iron, united to the ends of the long wrought-iron tubes at the time
of casting such curved pipes; and the union of the cast iron with the
wrought iron may be facilitated by applying borax around the ends of the
wrought iron before it is laid in the mould, as is well known and commonly
practised for casting the central bosses for wheels of locomotive steam engines
around wrought-iron tubular arms. For such wheels a suitable size for cast-
iron pipes is three inches in diameter inside and four inches outside, the cast
iron being half an inch thick; or, for wrought iron, two and three quarters
inches diameter inside and three inches outside, the wrought iron being one
eighth of an inch thick; but such dimensions may be varied. And the interior
of piping of any of the arrangements, Figs. 3, 6, 7, 8, or 9, may, if preferred,
be kept supplied with hot water instead of steam, provided a continual and
rapid circulation of the hot water is kept up. In such case a hot-water boiler,
set over a suitable furnace, may be connected by a pipe or pipes proceeding
from the highest part of the boiler to join to the entrance pipe, such as shewn
dotted at p, Fig. 3, or shewn at G, Figs. 6, 7, 8, and 9, so as to introduce hot
water therefrom into the interiors of all the pipes, in the same manner as
already described respecting steam; and in order to keep up a circulation of
the water the exit pipe w, Fig. 3, or H, Figs. 6, 7, 8, and 9, being connected
by a pipe or pipes with the lowest part of the said hot-water boiler, will return
the water thereto after it has become somewhat cooled by running through the
interior of the piping and communicating heat to the brine by which the
piping is surrounded; in all cases adequate safety valves being provided for
the escape of steam which may be formed within such boiler, or any excess
of steam which may become accumulated to a higher pressure than is intended
to be use:l.
And as to the use which may be made of apparatus constructed as
herein-before described, the manufacturer may adopt one or other of the
aforesaid different arrangements according to circumstances, and to the kind

page_text: of salt he wishes to make. What I prefer is as follows, viz.:-To have a largo
salt pan on either of the constructions Figs. 3, 6, 7, 8, or 9, except that the
lower bottom A, A, and the sides B, B, are to be iron instead of wood, because
fire is to be applied in furnaces beneath that bottom to give heat to water con-
tained in the lower part of the space between the two iron bottoms a, a, and
A, A, that water resting on the iron bottom A, A, and being made to boil by
the direct heat of the fires in the furnaces beneath the said iron bottom A, A.
The steam which rises from the water ascends in the upper part of the space
between the two bottoms with an elastic force but little higher than atmospheric
pressure, and gives heat to the upper bottom a, a, and to the brine above the
same; and as to the water resulting from so much of the steam as is condensed
by so acting beneath the bottom a, a, all that water will drop down into the
water below to mix therewith, and be again raised into steam. And the fur-
naces beneath the bottom A, A, having large fires kept up in them, much
more steam will be produced in manner aforesaid than will be so condensed
beneath the bottom a, a, and that surplus steam will be available for use in
other ways, as will be explained. The pan now describing is in fact a
steam boiler as well as a salt pan heated by steam applied in a casing beneath
it. Part of the said surplus steam may be allowed to ascend into the interior
of piping disposed (according to either of the arrangements, Fig. 8, 6, 7, or 8)
within the brine of the said salt pan, in order to give additional heat to that
brine, for causing a rapid evaporation of water therefrom and a crystallization of
salt therein. But in case fine salt is required to be made in the said pan, then
it will be better to supply the interior of the said piping with high-pressure
steam, which will give more heat and a higher temperature to the brine; but
such steam must of necessity come from a suitable high-pressure boiler
through suitable steam pipes, and be kept distinct from the steam (of but little
more than atmospheric pressure) which is produced, as aforesaid, within
the space between the two iron bottoms A, A, and a, a. And any of
the arrangements of piping, Figs. 3, 6, 7, or 9, will suit for high-pressuro
steam, under the conditions already explained in reference to each Figure;
and the Blues from the furnaces beneath the iron bottom A, A, of the first
apparatus now describing, will pass onward beneath the lower bottom of
another second apparatus, which will be without any lower bottom A, A, or
sides B, B, but will be only the iron bottom a, a, and sides b, b, forming a
simple iron pan for containing brine; and the heat of the flame, heated gas and
smoke proceeding along the said flues, and acting beneath the bottom a, a,
will give heat to the brine above that bottom, in order to evaporate water
therefrom, and cause it to deposit salt, and which may be fine salt, because tho

page_text: brine may be kept at a sufficient temperature for that purpose, in consequence
of the rapid communication of heat by the secondary fire heat beneath the iron
bottom a, a, of the pan; and the same flues before mentioned will continue
further onwards beneath the bottom of another third apparatus like the last-
mentioned, that is to say, a simple salt pan with an iron bottom a, a, and
slides b, b, for containing brine (without any lower bottom A. A, or sides B, B).
the heat of gas and smoke passing along in the said flues, and acting beneath
the bottom a, a, will communicate heat to the said brine for evaporating water
and producing salt therefrom, which will be of the kind called broad salt,
because the diminished heat in the flues will not keep up the brine to a
sufficient temperature for making fine salt; and after having passed beneath
the last-mentioned or third apparatus, the same flues aforesaid will continue
still further onwards to pass into and through a stove before arriving at the
vertical chimney stack, so as to heat the air within the stove for the purpose
of drying the masses or squares of fine salt, which are placed in that stove.
Wherefore, to recapitulate the particulars aforesaid, the direct action of the
fires in the furnaces beneath the lower iron bottom A, A, of the first apparatus,
gives heat to the water that is contained in the space between the two bottoms
of that apparatus so as to raise steam from that water (in the manner of a steam
boiler), and part of such steam communicates heat to the brine which rests on
the upper bottom a, a, and, together with the assistance of the heat of steam
in the interior of the piping, produces salt from the brine, which salt may be
of the kind called fine broad salt, if the said steam wherewith the piping is
supplied is only a little stronger than atmospheric pressure; but it may be of
the kind called fine salt if high-pressure steam is supplied to the piping.
Then the secondary heat proceeding from the said fires through the flues and
beneath the one iron bottom a, a, of the second apparatus, gives heat to the
brine which rests on that bottom a, a, and produces fine salt from the said
brine, and then the diminished heat in the continuation of the flues beneath
the one iron bottom a, a, of the third apparatus, gives heat to the brine which
rests on that bottom, and produces broad salt from the said brine. And
besides the aforesaid three apparatuses, which are so heated in succession by
direct and secondary and diminished action of the fire, as aforesaid, as many
other additional apparatuses may be also heated by surplus of the steam that
is produced in the space between the two bottoms of the first apparatus, together
with such accession of high-pressure or other steam from suitable steam
boilers as may be required. The said surplus steam is for such purpose to be
conveyed by suitable steam pipes from the said space between the two bottoms
of the first apparatus to the different places where such steam is to operate in

page_text: the said additional apparatuses, each of which will be constructed with a
wooden bottom A, A, and sides B, B; and it may also have an iron bottom a, a,
and sides b, b, such as in Fig. 8 or Fig. 9, in order to form an iron pan for con-
taining brine, with a wooden casing for steam beneath the iron bottom and
around the sides of such iron pan, but all the piping represented in the Figures
is to be omitted. The said surplus steam being supplied by the steam pipe
into the space between the wooden bottom A, A, and the iron bottom a, a, will
give heat to the brine, which is resting upon the iron bottom, by transmission
upwards through the metal, and the wood, by its non-conducting nature, will
prevent waste of heat; and all the water resulting from the condensation of
steam beneath the said iron bottom a, a, will drop down upon the wood
bottom A, A, and as such water collects thereon it must be conveyed away
by a suitable drain pipe or pipes and returned to the space between the
two bottoms of the first apparatus, from whence the surplus steam
proceeded (as from a steam boiler), in order so far to replenish that space
with water. And note, in order to facilitate the collecting of water upon
the wood bottom A, A, it may be somewhat lower at one end (or the
middle part of the bottom A, A, may be lowest), or at one corner, than
at other parts, in order that the water may run down to the lowest part, and
the said drain pipe should be connected to the said lowest part to take away
the water therefrom. And in order that the said water may run back with
facility through the said drain pipes, to return to the space between the two
bottoms of the first apparatus, each of the additional apparatuses now describing,
which is supplied with steam from that space (as from a steam boiler), should
be situated at a higher level than the first apparatus, which may be con-
veniently done by placing the said additional apparatuses ou an upper story or
floor over the three first apparatuses, whereby much less space will be occupied
than in ordinary salt works. The said additional apparatuses, when situated
on the upper story or floor, are to be supported on cross beams and joists, with
such bearing walls, or pillars and posts, or props, as will firmly sustain their
weight. And, to prevent any accidental droppings of water from the under
sides of the wood bottoms of such upper apparatuses falling into the brine in
the pans beneath, slated or other roofs may be placed over the said brine and
beneath the said wood bottoms, so as to intercept all such droppings, and with
suitable gutters for carrying off the same, without allowing any to fall into the
brine beneath. Or the said additional apparatuses (or some of them) may be
made without any iron bottom a, a, and sides b, b, and then the wooden
bottom A, A, and sides B, B, will contain the brine as in a wooden pan or
cistern, within which piping is to be applied according to any of the arrange-

page_text: ments, Figs. 3, 6, 7, or 8, as regards the piping alone; but that piping being
placed in the wood vessel or pan A, A, B, B, in the same manner as the piping
in those Figures is represented to be placed in the iron pan a, a, b, b, and surplus
steam from the space between the two bottoms of the first apparatus is to be
supplied to the interior of the piping, as from a steam boiler through a steam
pipe, in the like manner as already explained respecting the supplying of such
steam to the space between two bottoms of an additional apparatus, except
that the said steam pipe is to be joined to the entrance pipe of the piping
(p, Fig. 3, or G, Fig. 6, 7, 8), so as to introduce a constant supply of steam
into the interior of the piping, in order that it may give heat by transmission
through the metal of the piping to the brine by which it is surrounded, and
that transmission will have the same effect, and will be an equivalent for the
transmission before mentioned of heat through metal of the iron bottom a, a,
in the case already described of such an iron bottom being used; and all
water resulting from the condensation of steam within the interior of the piping
will run therein to the exit pipe (w, Fig. 8, or H, Figs. 6, 7, 8), and must be
conveyed therefrom by a suitable drain pipe, to return to the space between
the two bottoms of the first apparatus from whence the surplus steam
proceeded. Or otherwise, the interior of the said piping (which is so placed
as aforesaid within the wooden vessel or pan containing the brine) may be
supplied with high-pressure steam so as by the heat thereof to keep the brine
heated up to a higher temperature than would be the case if the same piping
were to be supplied with steam only a little stronger than the atmospheric
pressure, such as the steam which in the case already described is supplied to the
space between the wooden bottom A, A, and the iron bottom a, a. The high-
pressure steam must be supplied from a high-pressure boiler of any suitable
kind, by a steam pipe extending therefrom to join to the entrance pipe of the
piping (as p, Fig. 8, or G, Figs. 6, 7, or 8), and the water resulting from the
condensation of high-pressure steam within the interior of the piping must be
conveyed from the exit pipe (w, Fig. 3, or II, Figs. 6, 7, or 8) by a suitable
water pipe, to return such water to the said high-pressure boiler in order so
far to replenish the same with water. The same high-pressure boiler which
thus supplies high-pressure steam to the piping in the additional apparatuses
now describing (or such of them as are so supplied) may also supply high-
pressure steam to the piping of the first apparatus (in case of that piping being
so supplied as herein-before mentioned); and such high-pressure boiler should
be situated at a lower level than the said first apparatus, in order that all the
water resulting from condensation of high-pressure steam in the piping of the
first apparatus, and of the additional apparatuses (or such of the said

page_text: apparatuses, as have their piping supplied with high-pressure steam)
may run back into the high-pressure boiler, in order so far to replenish
the same with water; and although the high-pressure boiler will be thus
replenished with nearly as much water as is evaporated from it in steam,
yet, as there will be some waste by steam escaping at the safety valve
or valves and by leakage of steam or of water, there must be a feeding
pump provided for forcing water into the boiler at such times and in such
quantity as may from time to time be required; and the said high-pressure
boiler must also be provided with the usual gage cocks, or other means of
ascertaining the quantity of water. in the boiler, and all other appendages of
ordinary high-pressure boilers. Or otherwise, the said 'additional apparatuses
(or some of them) may be made with a wooden bottom A, A, and sides B, B,
and also with an iron bottom a, a, and sides b, b, so as to form an ironi
pan for containing brine, with a wooden casing for steam beneath the bottom
and around the sides of such iron pan, which is also to have piping within it,
as represented in either of the Figs. 8, 6, 7, 8, or 9. And surplus steam from
the space between the two bottoms of the first apparatus is to be supplied (as
from a steam boiler) to the space between the wood bottom A, A, and the
iron bottom a, a, of the additional apparatus now describing, in order to give
heat to the brine above the iron bottom a, a, by transmission of heat upwards
through the metal of that bottom; and steam is also to be supplied to the
interior of the said piping, in order to give heat to the brine wherwith the
piping is surrounded, by transmission of heat through the metal of the piping;
so that in the case now describing' there will be a twofold communication of
heat to the brine contained in the additional apparatus. And the said supply
of steam to the interior of the piping may be derived from the steam where-
with the space between the wood and iron bottoms of the same additional
apparatus is supplied, such steam being in that case allowed to ascend from
the said space into the interior of the piping, as already explained in reference
to Fig. 3; and the water resulting from the condensation of steam within the
said interior being allowed to descend into the sail space either from the exit
pipe (such as w, Fig. 3, or H, Figs. 6, 7, 8, or 9), or else through the open
ends of inverted syphon pipes,' as already described in reference to Fig. 8, so
as by one or other way the said water may drop down upon the wooden bottom
A, A, to mix with the water, which also drops down thereon from condensation
of steam beneath the iron bottom a, a. And all the water which so collects
on the wooden bottom A, A, from both the said sourses will be returned; as
already explained, to the space between the two bottoms of the first apparatus ;
or the interior of the piping may be supplied with high-pressure steam for

page_text: producing the said twofold communication of heat to the brine in the said
additional apparatus now describing, in order by that means to give more heat
to the brine, and keep the temperature thereof higher than would be the case
if the same piping were to be supplied with steam only a little stronger than
atmospheric pressure. Wherefore to recapitulate the particulars aforesaid
respecting the said additional apparatuses they are in all cases to have wooden
bottoms A, A, and sides B, B, and in most cases are to have iron bottoms a, a,
and sides b, b, as well as the wooden ones. The brine above the iron
bottom a, a, may be beated by a simple application of steam supplied to the
space between that and the wood bottom A, A, as the sole means of giving
heat to that brine without any application of piping. Or otherwise, the addi-
tional apparatus may be adapted to be further heated by steam supplied to the
interior of piping immersed in the brine, in addition to the steam supplied as
aforesaid to the space between the two bottoms, so as to produce a twofold
communication of heat to the brine, the steam so supplied to the interior of
the piping being either steam only a little stronger than atmospheric pressure,
or being high-pressure steam for producing the greatest effect of the said two-
fold communication. Or otherwise, the additional apparatus may have only a
wood bottom A, A, and sides B, B, for containing the brine in the wood pan
or cistern (without any iron bottom or sides thereto), and with piping applied
in the wood vessel, to be supplied with steam in the interior of such piping
as the sole means of giving heat to the brine by which the piping is
surrounded, the steam so supplied being either steam only a little stronger
than atmospheric pressure, or being high-pressure steam. And the said
additional apparatus (or one or other of them) may be constructed and
used in one or other of the various ways as aforesaid, according as the
manufacturer may prefer, and according to the fineness of salt he requires to
make. The simple application of steam only a little stronger than atmospheric
pressure, whether in the space between two bottoms or in the interior
of piping, will be suitable for making broad salt, which does not require the
temperature of the brine-to be kept up so high as is requisite for making finer
salt. The simple application of high-pressure steam in the interior of piping
(without any other concurrent application of heat) will keep the brine at a
higher temperature, and make broad salt of a finer grain. And the twofold
application of steam between two bottoms, and also within the interior of
piping, will communicate hent very rapidly to the brine, and in case of the
said steam in the piping being high pressure, it will keep the brine at a still
higher temperature, so as to produce fine salt; and one or other of the
different arrangements of piping Figs. 3, 6, 7, 8, or 9. may be used according

page_text: as it is required to have a greater or less extent of heating surface brought
into action upon the brine; the greater that extent the more rapid will be the
communication of heat to the brine. Figs. 8 or 9 are suitable for salt pans of
great width, wherein the salt is gathered by raking it from the middle towards
both sides of the pan, as the ends of the piping may be arranged so as to leave
clear spaces along both sides of the pan for taking out the salt. And whereas
it is desirable that the brine should be made hot before it is introduced into
the pans wherein salt is to be made from it, the preparatory heating of the
brine may be performed in one or more of the aforesaid additional apparatuses,
which is or are constructed in any of the ways already described for such
apparatuses, cold brine being introduced with a continual stream into one end
of the open pan of such apparatus, in order that the brine may become heated
therein by the application of steam, either between the wood and iron bottoms
thereof, or else within the interior of piping, or applied in both those ways, as
already fully described; and the hot brine overflowing in a like stream from
the opposite end of the said pan may be thence conveyed in suitable pipes to
the several open salt pans of the different apparatuses, in order to keep each
one properly supplied by a continual influx of hot brine. But the mode which
I prefer for preparatory heating of brine is to pass it through iron brine pipes,
which are kept heated by being laid horizontally within the space between the
two iron bottoms of the first apparatus aforesaid, viz, that apparatus which
has fire applied in furnaces beneath beneath the lowest of those two iron
bottoms, so that the said brine pipes will be surrounded by the hot water or
the steam in such space, in order that brine flowing in a continual current
through the interiors of such pipes may become heated therein. The brine
may descend from an elevated reservoir through suitable pipes which join to
one end of each of the said heated brine pipes, so that the brine will enter at
that end in a cold state, and will become heated in flowing through the length
of the said heated pipes, in order to pass out at the other end, and be conveyed
away therefrom in a heated state through suitable pipes, which join to the
last-mentioned ends, and go from thence to the several open salt pans of the
different apparatuses, in order to keep each one properly supplied by a
continual influx of hot brine. Or like brine pipes may be so applied as
aforesaid within the steam spaces between the wood and iron bottoms of any
of the additional apparatuses aforesaid. And note, the said mode of running
the brine through brine pipes kept heated by being included in such
spaces between two bottoms, so as to be surrounded by the hot water, or
the steam therein contained, forms no part of my present improvements,
although of my invention, being part of improvements for which former

page_text: Letters Patent were granted to me on the Third day of March, One thousand
eight hundred and forty-five. And note, although it has been described that
the spaces between the wood and iron bottoms of all the several additiona
apparatuses (and also in some cases the interiors of the pipings in those
apparatuses) are to be supplied by the surplus of steam that may be produced
within the space between the two iron bottoms of the first apparatus (viz
that apparatus which has fires applied in furnaces beneath the lowest of those
iron bottoms), nevertheless it is to be understood that the said space in yielding
its surplus steam for the supply of the said additional apparatuses only
operates as any ordinary steam boiler would do, and therefore any accession of
steam (a little more than atmospheric pressure) that may be wanted for the
supply of the additional apparatuses beyond the said surplus, may be supplied
from one or more such boilers, which may be a steam boiler of any construction
that is suitable for supplying steam of little more than atmospheric pressure,
and such boiler or boilers may be used for making up any deficiency of the
said surplus steam; in which case it will be best to supply such accession of
steam along with the said surplus of steam, so as to make one common and
ample supply of steam to all the apparatuses which are working in concert,
in order that every one may be fully supplied, except as to such supply
to the interiors of the pipings as may be preferred to be high-pressure
steam, which must of necessity be supplied from a high-pressure boiler or
boilers, and must be kept separate from the other steam of little more than
atmospheric pressure; but, as already explained in reference to Fig. 9, a
portion of the high-pressure steam (or any excess thereof) may be let out
through loaded safety valves into the space between the wood and iron bottoms,
so as to become an accession to the steam in that space. And I prefer for
such high-pressure boilers to employ what are called tubular boilers, because
numerous small tubes of thin metal are used for the internal flues within such
boilers, those tubes being surrounded by the water in the boiler, and serving as
the flue passage for causing the current of flame, heated gas, and smoke,
(during the passage thereof from the fires in the furnaces to the vertical
chimney), to pass in numerous small divided currents through the water by
which the said tubes are surrounded, so as to communicate heat to the water
by transmission through the thin metal of the tubes. The construction of such
tubular boilers is well known, as they are in common use for high-pressure
steam in locomotive engines for railways, and similar tubular boilers are also
commonly used in steam vessels; the latter sort are most suitable for my
purpose, because the tubes are of sufficient size to permit of the use of coal
for fuel, without clogging up the interiors of the tubes with soot. A tubular

page_text: boiler such as those used in steam vessels being made of great strength in all
its parts suitably for retaining high-pressure steam, and having proper safety
valves, and all the appurtenances belonging to a complete bigh-pressure boiler,
will be the best means of supplying high-pressure steam to the interiors of the
piping of any of the apparatuses herein-before described. And, as herein-before
mentioned, if a steam engine is required, it may be a high-pressure engine, and
may be worked with some of the high-pressure steam from the same tubular
boiler aforesaid, and the waste steam that .is discharged by the said engine
may be used in the apparatus, or in part thereof, in any of the ways that
have been herein-before mentioned of using steam but little stronger than
atmospheric pressure.
Having now described my said improvements, I, the said George Ellins, do
hereby declare that the new Invention, whereof the exclusive use is granted to
me by the Letters Patent herein-before recited, consists in the following
particulars, that is to say:―
Firstly, the improvement herein-before described and represented in the
several Figures of the Drawing hereunto annexed of cast or wrought iron
piping to be disposed within the brine in a open salt pan, for the purpose of
communicating heat to the brine from steam or hot water which is supplied
to the interior of the piping. And whereas it is a not a new idea to apply
steam within coils and ramifications of pipes for heating and evaporating
liquids for various purposes, this part of my improvements is for the peculiar
arrangements of suich piping, as herein-before described; either in a zigzag
course, as in Figs. 1, 2, 3, with entrance and exit communications alternately
at suitable intervals along such course, or else with pipes in detached parallel
rows across the pan, and one pipe above another in each such row, as in
Figs. 4, 5, 6, also Fig. 7 and Fig. 8, or with only one pipe in each such row,
as in Fig. 9, and in each case with entrance and exit communications at the
opposite ends of the pipes in each row; the peculiar arrangement in every
case affording uninterrupted entrance for steam or hot water. into and free exit
for water out of the interiors of the piping, which exposes extensive surfaces to
the brine for heating the same, but nevertheless leaves clear spaces between
the rows of pipes for gathering the salt by raking it (without interruption, by
the piping) along the bottom of the pan towards one or both sides thereof,
which is or are left clear for taking out the salt; the steam wherewith the
interior of such piping is supplied being either steam only a little stronger
than atmospheric pressure or else high-pressure steam, according to the tem-
perature that it may be intended to keep up in the brine; such piping to be
used in various ways herein-before described, according to circumstances, the

page_text: simplest of those ways being to apply the piping within a wooden vessel or
cistern or salt pan containing brine without any other mode of applying heat
to that brine, but the wood, from its slow conducting nature, will economize
heat by preventing escape thereof downwards or sideways through the bottom
or sides of such wooden vessel.
Secondly, the combination herein-before described of such piping as afore-
said with an application of steam or of hot water beneath the iron bottom of
a salt pan containing the brine wherewith the piping is surrounded; the said
steam or hot water being contained within a space left for its reception
between the said iron bottom of the salt pan and another under-bottom of
iron, beneath which fire heat is applied for beating the said water, and by
means thereof, or of steam arising from such water, heat is communicated to
the brine by transmission upwards through the upper iron bottom of the salt
pan, in addition to the beat that is communicated at the same time to the
brine by the steam or hot water within the piping; wherefore the said com-
bination produces a twofold communication of heat to the brine. And in
case of the piping being supplied with high-pressure steam the brine may be
kept by the heat thercof at a higher temperature than can be done with steam
but little stronger than atmospheric pressure.
Thirdly, the combination herein-before described and represented in Figs. S,
6, 7, 8, or 9, of such piping as aforesaid, with an application of steam or of
hot water, beneath the iron bottom of a salt pan containing the brine where-
with the piping is surrounded; the said steam being contained within a spaco
left for its reception between the said iron bottom of the salt pan and another
under-bottom of wood, which, together with wooden sides around that wooden
bottom forms a steam casing or water casing for retaining steam or hot water
beneath the iron bottom and around the sides of the salt pan; the steam or
hot water being supplied to the said space by pipes from a suitable boiler, and
giving heat to the brine by transmission upwards throught the upper iron
bottom of the salt pan, in addition to the heat that is communicated at the
same time to the brine by the steam or hot water within the piping; where-
fore the said combination produces a twofold communication of heat to the
brine; and the wood, from its slow conducting nature, will economize heat by
preventing the escape thereof downwards or sideways through the bottom
or sides of the said water or steam casing. And in case of the piping
being supplied with high-pressure steam, the brine may be kept, by the
heat thereof, at a higher temperature than can be done with steam but little
stronger than atmospheric pressure. And as to any part of such high-pressure
steam that may make its escape from its confinement, by lifting up
loaded

page_text: safety valves, which are situated within the space between the wood and iron
bottoms a, a, and A, A, (as herein-beforo described in reference to Fig. 9), the
steam so escaping into that space will, by diffusing itself therein, become steam
but little stronger than atmospheric pressure, and will, therefore, operate as an
accession to the quantity of like steam wherewith the said space is to be sup-
plied by pipes from any kind of steam boiler, as already explained. By thus
placing the loaded safety valves within the said space, waste of the high-
pressure steam by excess thereof will be avoided, because all that does escape
will be usefully employed. And note, the said disposition of such loaded
safety valves within the said space may also form part of the combination set
forth under the head Secondly.
Fourthly, the combination herein-before described of a wooden bottom and
sides with an iron bottom and sides, as is represented by A, A, B, B, and a, a,
b, b, and e, e, in Figures 3, 6, 7, 8, or 9 (supposing all the piping represented
in those Figures to be omitted); the said wooden bottom A, A, and sides
B, B, forming a steam casing for retaining steam in a space between the iron
bottom a, a, and around the iron sides b, b, of an open salt pan containing
brine, which is heated by transmission of heat upwards through the said iron
bottom a, a, and laterally through the iron sides b, b, from the steam which is
supplied to the wood casing A, A, B, B, so as to occupy the space beneath
the iron bottom a, a, and around the iron sides b, b, of the salt pan. And note,
allthough this combination of wood steam casing with an iron salt pan has
been herein-before described as one of the modes of constructing an additional
apparatus for making broad salt, to be supplied by surplus steam from a first
apparatus, which is for making finer salt, nevertheless this combination is
equally applicable for a first or principal or only apparatus for making broad
salt, if the wooden casing is supplied with steam from any suitable kind of
steam boiler, or with waste steam discharged from a high-pressure steam
engine. And whereas it is not a new idea to apply steam within a casing of
iron, so as to act beneath the iron bottom of an open salt pan for heating the
brine therein by transmission of heat upwards through such iron bottom; and
also it is not a new idea to construct open salt pans of wood to be heated by
currents of hot air or gas, and smoke or steam, passing through large iron
tubes or flues, within the brine contained in such wooden salt pan; no claim
is made under this fourth head to any combination wherein wood forms the
vessel or pan for containing the brine, nor to any casing for containing steam
which is made of iron, but only to the combination of wood for the steam
casing with iron for the open salt pan, the advantage of which is to economise
heat, from the slow conducting nature of wood preventing escape of heat down-
wards or sideways through the wood, as herein-before fully explained.