IMPROVEMENTS IN STEAM GENERATORS
Year: 1842

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GABRIEL
HIPPOLYTE MOREAU, of Leicester Square, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her present most Excellent Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Twenty-first day of December, in the sixth year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said Gabriel
Hippolyte Moreau, Her especial licence, full power, sole privilege and
authority, that I, the said Gabriel Hippolyte Moreau, my exors, adiñors, and
assigns, or such others as I, the said Gabriel Hippolyte Moreau, my exors,
adors, or assigns, should at any time agree with, and no others, from time
to time and at all times during the term of years therein expressed, should and
lawfully might make, use, exercise and vend, within England, Wales, and the
Town of Berwick-upon-Tweed, my Invention of "IMPROVEMENTS IN STEAM
GENERATORS;" in which said Letters Patent is contained a proviso that I, the
said Gabriel Hippolyte Moreau, shall cause a particular description of the
nature of my said Invention, and in what manner the same is to be performed,
to be inrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Gabriel Hippolyte Moreau, do hereby declare that the nature of my said
Invention, and the manner in which the same is to be performed, are fully
described and ascertained in and by the following statement thereof, reference
being had to the Drawings hereunto annexed, and to the Figures and Letters
marked thereon, that is to say:
One has tried various systems of generators to supply the steam boilers,
horizontal, vertical, and inclined tubes; everything leaves more or less to
desire; the enquiries continue; either the steam drives the water from those
tubes, or a regular feeding becomes impossible, or one obtains not enough
steam, or the expence of the combustible is doubled. However, it must
always have seemed strange, and even absurd, to use immense boilers,
containing ten or twelve thousand times more water than every piston stroke
consumes, whilst every piston stroke introduces as much as it wastes: what
is then than enormous reserve of water for? It serves chiefly, 1°, to fill
up sufficiently the boiler, which must necessarily be of a great capacity,
since it must offer a vast heated, surface, and that no portion of this surface
ought to be dry without the greatest danger; 2°, to make less sensible the
momentaneous variations in the progress of the fire, for a quantity of water
much less should acquire nearly instantaneously a very superior tension by an
excess of fire, and it should grow cold the same, as soon as the fire should
lose its convenient intensity; 3°, to remove all importance to the light
variations of the level in the boiler, and consequently to those of the feeding.
In fact, its surface at the water gauge being very much extended, one conceives
that should the feeding cease entirely one should have still time to perceive
the lowering of the level, the engine needing to work a pretty long while
to lower the level of two centimeters for instance. Those are, without speaking
of the difficulty of cleaning and others, the chief reason for the use of those
large, massy, and enormously weighing boilers, requiring excessive expences
for the establishing, a very long time to heat, and the continual risks of the
frightful ravages of an explosion. To supply those boilers by tubulous
apparatus containing but a small quantity of water, it is necessary to find means
to realize indispensable conditions; there must be, among the rest, 1°, sufficient
surface for the heating; 2°, regular feeding, without possibility of having
neither more nor less water than is necessary for the constant level, in spite of
the variations more or less unavoidable in the expense of steam; 3°, surface of
water gauge nearly as extended as in an ordinary boiler, and whose guage can
only lower slowly if the feeding ceases or diminishes; 4°, the certainty that
the steam must drive the water from that apparatus more than from an

page_text: ordinary boiler; 5°, horizontal and warranted communications of the tube,
forming a common tie both for water and steam; 6°, easiness of cleaning;
7°, means by which the excess of tension of the steam moderates itself the fire
instantaneously, for, if the fire then continued with a certain intensity, the tension
should soon rise by one or several atmospheres, or the valve opening there should
be a spending without any advantage. It is true that if all the difficulties
were to be reduced to that seventh condition, the apparatus should present
besides so many advantages that one could remedy to it by a greater attention in
the managing of the fire, and by the choice of an intelligent fireman, but it is not
so, and the other conditions are of the utmost necessity. It is, therefore, obvious
that, by realizing these conditions, immense advantages should realize with them.
Among the number, the apparatus would cost but about the fourth part of
the price of a boiler; the space it would occupy would be much less; its
weight should be twenty, forty times less; some minutes only would be required
to heat; there could be no explosion, and besides, all should be limited in
the tearing of some tubes without any other misfortune. Theorical and ex-
perimental enquiries have led me to resolve the problem by a system of tubes
conveniently disposed. Tubes may be disposed in many ways; many ways
also may make them communicate between each other; the good one differs,
perhaps, but very little of all the others materially, but one must have applied
one's self with perseverance to such enquiries to understand what pains, time,
and expences are necessary to arrive to discern those decisive differences, and
the more difficult to recognise as they strike the eye the least, by reason
of their little appearance and material importance. After having uselessly
sought to modify the several known tubular systems, obtaining nothing satis-
factory with them, I finished to think that I began thus to engage in a wrong
way, and that it was better for me to choose my starting point and my way.
I thought that a flat boiler, having only ten or twelve centimeters in depth,
that is to say, between its two upper and lower parts, though receiving but
very little water, should present a great heated surface, a great surface of gauge,
little weight, &c., &c.; that the solidity on the contrary was alone much less. I
also perceived that in principle one could preserve that form, and that it should
be sufficient to supply the boiler to fill the same space by a certain number
of tubes, of 10 or 12 centimeters about for instance. I place tubes horizontally
on the same plane, parallel to each other, and almost in contact to a score of
centimeters, or about 7 or 8 English inches above the grate of the furnace; the
means of communication among each other should be so as one removes the least
possible from the flat boiler I have just spoken of, the tubulatings and orifices
of communication will then have their axis in the plane of the axis of the

page_text: tubes composing the system. These communications should have the greatest
diameter possible, as great as that of the tubes of the system will be the best.
Any means of communication above, under, or at length out of the plane of the
axis has inconveniences; and it is necessary, as I have said it, that the same
communication of the tubes with each other be common both to water and
steam. Attached to the principle of the flat boiler, and representing it the
most simply possible, I place the tubes as I have said on the same horizontal
plane; to place some higher or some lower, or to make more than one rank, or
to gather them as it were in a pile, is running to numerous inconveniences;
above the general plane of the axes one can admit but tubes for steam and not
at all for water. One must also renounce to feed the apparatus by the upper
part, it is convenient to cause the water to come under the tubes. The feeding
must be made very regular; the water must arrive there having already
a temperature equal to that which is already within. One must be very careful
not to give too much thickness to the brass with which the tubes are made, the
indispensible thickness in the large boilers being one of the principal causes of
their bursting. For tubes of twelve centimeters, or about 5 inches in diameter,
the thickness of a millimiter and a half, or about the 24th part of an inch, is
more than sufficient, the tube resisting thus to a pressure of about 50 atmo-
spheres. I stand to these preliminary remarks; they seemed to me fit to make
better understand the apparatus; the remainder will resort from the description
I am to make of it.
The Fig. 1 presents the plane of the apparatus; the Fig. 2, the elevation
of the side of M; and the Fig. 3, the profile on the line N, O, of the
Fig. 1, and N', O', of the Fig. 2. The same letters have the same signifi-
cation in the 3 Fig. A, B, is an horizontal tube, giving the communication
between the nine other tubes which are perpendicular to it. Each. of
these is composed of two ends; thus, a, b, is composed of two ends a, y, y', y",
attached to the transversale tubes A, B, soldered and nailed in those junctions
for more solidity. The axis of all these tubes are in the same horizontal plane.
The tube A, B, is of a little larger diameter than the others, so that the nine
other tubes representing the boiler, have, between them, communications of a
greater diameter than theirs. It is understood that, according to the dimen-
sions of the apparatus, it will be possible to use two or more transversal tubes
A, B. The anterior end A carries an index of the gauge by means of a glass
pipe in the ordinary way; it is understood that one can adapt cocks to it to
shut off, in case the glass pipe should break, or when required to clean them.
Each of these tubes a, b, a', b', has one of its ends fixed to the bottom, and the
other by a cover, shutting by means of briddles and bolts, or still better, as is

page_text: seen by means of a single pressing screw V, V, in order to open and shut more
quickly for cleaning or for other motives. One sces also, that the ends closed
or fixed a, a, do not go so far; they leave thus the necessary place for the
shutting of the others, and can be in the furnace whilst the others project
without the sides of the furnace, being indicated by the lines c, c, d, d,
and c¹, c, d, d'. As to A it projects outside, as may be seen by the lines d, d,
and d', d, indicating the side. Out of the two following means, which may be
used to open and shut the chimney in order to regulate the tension of steam, I
have stood to produce the last one, the superiority of which is incontestable, see
the Fig. 2. One disposes a small paddle wheel of about 20 centimeters or about
7 inches in diameter, so as when a safety valve rises by the excess of tension of
the steam, the gush of steam which escapes strikes the float of the wheel and
makes the wheel turn. The shaft of this wheel has a pinion taking into
another cog wheel (to multiply sufficiently force at the expence of quickness);
at the shaft of this last one, using as axle-tree, is attached the end of a cord,
the other end of which is tied to a plate or disk, destined to shut and open the
chimney; when the excess of tension of the steam raises the valve, the small
paddle wheel turns the cord rolling on its axle, draws the plate, and closes the
chimney; the firo lowering, the tension encreases no more, it soon diminishes,
and then the valve fals again; nothing more touching the float of the small
wheel it stands free and motionless, and a weight brings back the plate to the
first place and thus makes open the chimney. To make the whole gush of
steam go out on one side, that of the little paddle wheel, one shall make but
one lateral opening to the valve. The manner to fix those pieces being easy
and ad libitum, depending also on circumstances and localities, it is useless to
describe it here by figures; one may want one or several returning pullies for
the cord.
Here is now the second means shown, part in elevation part in profile,
Fig. 2. C, D, is a cylindrical rod loaded with a weight P, convenient for
the tension one wishes to have passing through a tow box A, T, and en-
gaging in a tube A, B, which, soldered to the apparatus, prolongs itself there
almost to the bottom in water, so that the pressure of steam will cause the
water to ascend into the tube. That water presses the rod C, D, from the
lower part to the upper. When the tension overcomes the load, the rod will
ascend and will make play the lever E, H, F, which will shut by the end F the
register of the chimney. The tension diminishing the load will cause the rod
to come down again and open anew the register. The rod will come down
only when the tension is less then to make it ascend, and the difference may be
of and even an atmosphere during some instances. If one pleases to

page_text: make disappear this difference or make it insignificant, one must do so as to
have the load of the rod more considerable when it is up. For that purpose
in G, the end of a prolonging of the lever E, F, let us place a small
vase G¹, shown in verticle profile here to let see the inside part, in which is
a little valve with the rod S opening from the lower part to the upper at
the bottom of the vase. In the present moment the excess of tension of the
steam is supposed to have made the rod C, D, ascend, and have shut the
register of the chimney; thus the vase G¹ must have ascended, and the button b
of the rod s has pushed from the lower part to the upper the rod 6 a of the
clapper of a valve e, placed in the bottom of a larger superior vase V. This
vase is conditioned in the principle of an intermittent fountain tightly shut; it
admits air but by the tube T¹. When the valve e is opened, the water runs
from the larger vase into the little one till it comes to stop the lower extremity
of the tube T' which plunges into it. The encrease of weight which produces
this water makes the rod C, D, come down as soon as the tension of the steam
begins to diminish. The lever and the little vase will take the position
indicated by the dotted draught, and the chimney opens. Here, the lower
end of the rod of the clapper of the valve of the little vase meets the obstacle X,
and the valve being to open this vase gets empty, ready to reascend when the
same circumstance return. The larger vase V is shut at the upper part by a
tapped cork y, having a rod by which one lifts it up when one wishes to let
enter into the vase the water which shall have been poured into a receiver U,
furnished by the prolonging of the vertical sides of the same vase; the cock y
keeps always the air, being covered with water. One can do so, as when the
valve is opened the water passes through a cock adapted at the bottom of a
little box Z, placed below the receiver, soldered to the vase V; one will open
that cork at the degree which one will please. The rod of the clapper passes
through the bottom of the said box, a hole being made for that purpose; there
is no matter for some drops of water passing too. Let us suppose the excess
of tension takes place even 48 times within 24 hours, and that at every time
the little vase G₁ exhaust half a litre of water, it will be sufficient to pour
once 24 litres of water into the larger vase, not to care about it during 24
hours of working, which is absolutely insignificant. It is obvious that one may
change the position of the lever together with its length, and dispose the
system as one pleases; also, if one wishes to push the steam out of the boiler
without causing it to pass through the cylinder, one must establish a valve or a
cock for its cleansing.
The Fig. 6 represents the vase G on a larger scale. One pretends that
percarburated hydrogen gas can accumulate and detonize in the vent holes

page_text: if one shuts the register of the chimney; however, I see no danger in it,
but for all safety one has but to make an opening down the chimney and
shut it, but with a shutter opening without remaining free, and ready to open
at the least internal pressure. G, G¹, are vertical tubes united in communi-
cation by H, bearing the tubulatings h for the manometer, and h' for the
taking of steam. I is a vertical tube placed on the upper part of the boiler,
whose thickness separates it from the tube I', and of which it is the prolonging
in the same axis. The feeding water comes in I¹, and so in all the horizontal
system by k, k'. L is a valve for the overflowing. In I, I', is a floater, re-
presented by the dotted lines m, m¹. This floater shuts and opens the com-
munication in n. The Fig. 4 represents the profile of that part of the
apparatus with the same letters for indication. The weight of the floater being
such as when you plunge it into the water, it sinks into it till u; it is obvious
that as soon as the water gauge will be to that eight in the whole apparatus,
the opening in n will be shut, and no water will be permitted to come in, since
it comes under, and is enclined to strike the floater to the opening n. The
water which is pushed by the feed pump escapes through the valve L, a little
more loaded than the rod C, D, described further. As soon as the level begins
to lower, the floater goes down and the water comes in. It will be necessary to
give guides to the floater that it may always move vertically, and at the same
time to present an obstacle to the water which arrives by k, and could make it
deviate from its vertical position. I, I', is found is the interior of the furnace,
except the upper end which can surmount the arch indicated by the lines
d, d', Fig. 2, and d, c, Fig. 3, as H, G, G. As to the lower part I' it is in the
fire place and ash pan. P, P, Fig. 2, and P¹, P", Fig. 3, are the elevation and
profile of the grate; this grate has an opening to let pass freely I¹, which
besides in the fireplace will be preserved from the contact of the coals by a
vertical screen. The arch gets warm undoubtedly, but much less than should
be thought at first, the tubes being as near as possible, and the vent hole T,
whence departs the chimney F, being low enough, besides, the radiation of the
vault cannot surpass the radiation of an ordinary boiler. I have already said
that the dotted lines c, c, c¹, c', and d, d, d', d', Fig. 1, marked the sides of the
furnace, across which were prolonged without the ends close not fixed. I add,
that the metal of the tubes must not be in contact with the masonry. The
Fig. 4 presents the external front of the masonry on the side of the ends
not close fixe. The openings 1, 2, 3, 4, 5, are to receive the tubes 1, 2, 3, 4, 5,
of the Fig. 1. The circular zones Z, Z, are filled with sheet iron, which is
alone in contact with the tubes. The masonry stopping at a certain distance,
it is sufficient to place at the exterior part of the masonry bands of sheet iron

page_text: metallic disks.
stoutly fixed to the iron of the furnace, and bearing the cuts which form the
openings 1, 2, 3, 4, 5; one places the apparatus on the lower band cut, then one
places the upper band. One may do so as to have the upper part of the furnace
moveable on demand by supplying the masonry by sheet iron, making in that
case double vault and double sides as I have said. Sheet iron is to be preferred
to masonry; independently of its lightness, of the little space it occupies, and
thic economy of establishing, it presents but a reservoir of caloric, which gets cold
almost as soon as it is heated, and the means which acts of the fire by shutting
the chimney produces its effect more quickly. For the navigation on sea, the
great agitation to which the ship is exposed requires the employment of a means
to prevent the water of the tubes to obey quickly the motions, and to direct it
according to the inclination towards one of the ends of the apparatus, leaving
the other dry. Let us cause rod to pass through the centers of several
Let us fix them to that rod, leaving intervals between them,
their planes being parallel to each other and perpendicular to the very rod.
Let us introduce a rod thus supplied with disks or washers in each horizontal
tube of the system in order to avoid this inconveniency. The dotted line
N, r, r,r,r,r,r, N', indicates the rod in place with its disks, Fig. 1, 5. The
disks will clog the too quick circulation of the water without preventing it
entirely. Instead of being perfectly circular and having a diameter equal to
that of the tube, they should have the form which represents f, Fig. 6, 9, g, being
the vertical section of the tube, that is to say, the disk should be of a
diameter a little smaller, and a little segment will be taken from them to let a
certain liberty of circulation in its lower parts. This little apparatus can
casily be taken by one of its ends to introduce it into the tubes and to extricate
it. These disks may serve to sweep off the gravel which gets in the tubes.
In order to avoid too sensible an accumulation of water in the apparatus on
the side where the ship would be inclined by the wind, one may decompose an
apparatus in several, each of which having but two or three tubes, their
bending would then be insignificant. One may also, in the direction of the
length of the apparatus (which must always be the direction of the length of
the ship), make the apparatus itself bear upon two pivots in a manner
analogous to the suspension of a craddle.
I will finish this description in observing that I have thought useless
to occupy myself about the means of repairing the apparatus in case any
tube should burst. In fact, when we make an ordinary boiler, we don't
care about the means to repair it if it bursts. Then a boiler costs much
dearer and resists not so much as the tubes we are speaking of. There
is no need, then, to create difficulties gratuitously; the essential is to

page_text: establish well the apparatus and to try it with the hydraulic press under a
strong pressure even ten times that it is to bear, in order to be sure that the
solderings, joints, &c., present no flight. For these essays one shall not put
the floater m, m', Fig. 2 and 3, at the place which it occupies, unless it be
stopped down its course; otherwise it should prevent the water from filling
the apparatus. One shall only lay it in one of the horizontal tubes; the essay
will show whether it will itself resist to the pressure. We must observe that
the same pressure that would rend the tubes of the boiler would leave the
floater entire, as the tubes receive the strain of the hydraulic press in the
inside of their curvature, which tends to separate their molecules, whilst the
contrary effect is produced, for the floater which receives that strain on
the exterior part, and that shall resist because of its diameter, which is not so
large as that of the tubes of the boiler, even if we suppose less thickness to its
metal. If one wishes to have a greater steam reservoir, one can multiply the
vertical tubes in making them communicate to each other by others joining
them horizontally, as the example is to be seen in the Drawing, where is made
the taking of steam in h, h', Fig. 1, 2.
In establishing engines it is very rare when one does not make some
change, and often without perceiving that one can hurt the mother idea.
The principle one shall then remark well, that all the tubes composing
this boiler have their axis in the same horizontal plane; that the diameter
of the communications is not less, that it is even greater than that of the
tubes of the apparatus; that these communications are common both at
once to the water and steam; that the water gauge is at once in the
tubes and in the communications; that above the plane of the boiler
there are but tubes to serve as a reservoir or a dome, and which may be
multiplied accordingly to necessity. One may also observe that the feeding
tubes or of injection brings the water from underneath; that this water
coming in the horizontal apparatus is at a temperature at least equal to that
within; that for the constancy of the water gauge the floater becomes a
regulating valve, which opens and shuts an orifice, always covered by water,
since it is several centimeters below the gauge; that the water is maintained
in the total length of the tubes by disks placed perpendicular to their axis;
that that apparatus, though containing 20 and even 40 times less water than
an ordinary boiler presents as much heated surface and gauge; and, to end
this recapitulation, I shall direct the attention of the means which unites all
the conditions of economy, and which suppresses the safety valves as they
become useless because of the impossibility of danger. It is well understood
that one may establish several of these apparatus according to the wants and

page_text: localities, either on the same or on different planes, but always horizontal.
The communications between these apparatus are established by upper tubes
to concur to the same end and being to contain but steam. Every apparatus
will receive its feeding as I have explained. A single pump can be sufficient
for all, the injecting tube being ramified for that purpose according to the
number of the apparatus, which will have each its regulating valve with floater
as it has been said. I must still have foreseen the case where the apparatus
should be employed to uses where it should be exposed to shakes. In that
case, in fact, one would not load with a weight the rod sliding in a tow box,
and which steam makes go out to a certain point to shut the chimney when
the tension begins to overreach the limit. Doubtless one supplies the weight
by a spring in such circumstances for the ordinary valves, but here we must
find besides the means of regularizing the action of the spring the rod which
it loads having a pretty considerable course. For that I have recourse to a
principle analogous to that which is used in clock making to regularize
the action of the spring by the fusee. In Drawing No. 2, A, B, is the rod
that we know sliding in the tow box Q. It is cylindrical in its lower part
from r, and it is flat and toothed from r to A, making a catching with the
wheel P. G, G, is a kind of pulley with a concavity, having the same axis of
motion as the wheel P in I; but that pulley is not round, it is about an
ellipsis, as is seen. The Figure shows the profile of it by the middle of the
concavity and perpendicular to the axis. In G is attached a chain or a cord
which has its other end attached to the lower end n of a spring in helix, which
we see in a tube, of which we give the profile following the axis, in order to
let the interior be seen. This tube is fixed in e so as to be allowed to oscillate
on that point. This same tube is slit from L to M, so that a cross piece a, a,
can by coming down compress the spring, and the female screw L, L, is used for
that operation in order that the spring has at first the energy which is to represent
the weight which is supplied. Now, when the steam tends to pass over the
limit of necessary tension, the rod A, B, ascends, and by the lever X closes
the chimney. By ascending it causes the wheel P to turn, and the pulley
G, G', fixed on the same axis, but that pulley cannot turn without compressing
the spring from the lower to the upper part by the cord which is attached to it,
and one sees that by its form this pulley presents a circle shorter and shorter
as the cord rolls on it, and that by this means the energy of the spring becomes
more intense, which regularizes the effect. We have seen also in the preceding
description that the rod did not precisely come down as soon as the steam
would have lost the excess of tension if an overforce did not, as it were, shake it
and set in motion the overcharge furnished by an intermittent fountain, described

page_text: in the preceding addition, cannot also be used when there are shakes, as on a
carriage or a locomotive. We supply it by suspending a weight y to a spiral
spring R when the rod is ascended, and that its upper end is in A'; the very
shakes make it be struck by the vertical oscillations of the weight y, and so it
is set into motion, coming down as soon as the tension of steam is such as it
must be.
Having stated the nature of the Invention, and the manner of performing
the same, I would have it understood that I do not confine myself to the
precise details here shown, as long as the peculiar characters of the Invention
be retained, but what I claim is the mode of constructing steam generators,
as herein described.
I, William Henry Ritchie, of Lincoln's Inn, Gentleman, maketh oath and
saith, that he is acquainted with the handwriting of Thomas Pickford, Esq.,
the British Consul at Paris, and that he has examined the Specification of a
Patent granted to Mr. Gabriel Hippolyte Moreau, for Improvements in Steam
Generators, to which the signature of the aforesaid Thomas Pickford, is
attached, and he verily believes the said signature to be the signature of Thomas
Pickford, Esq., and that he was British Consul in Paris at the time such
acknowledgment was made.

page_text: AND BE IT REMEMBERED, that on the oath of William Henry Ritchie
the Specification aforesaid was enrolled, word for word, as above written. And
also the Specification aforesaid was stamped according to the tenor of the
Statute made for that purpose.
Enrolled the Twenty-first day of June, in the year of our Lord One
thousand eight hundred and forty-three.