CERTAIN IMPROVEMENTS ON OR CONNECTED WITH STEAM ENGINES
Year: 1825

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
CHARLES CHRISTOPHER RADDATZ, of Salisbury Square, Fleet Street, in the
City of London, Merchant, send greeting.
WHEREAS His present most Excellent Majesty King George the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fourteenth day of May, in the sixth year of His reign, did
for Himself, His heirs and successors, give and grant unto me, the said John
Charles Christopher Raddatz, His especial licence, that I, the said John
Charles Christopher Raddatz, my exors, adiñiors, and assigns, or such others
as I, the said John Charles Christopher Raddatz, my exors, adñiors, 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, and also in all His said Majesty's
Colonies and Plantations abroad, the Invention of "CERTAIN IMPROVEMENTS
ON OR CONNECTED WITH STEAM ENGINES," as communicated to me by Ernst
Alban, Doctor in Medicine, of Rostock, in the Grand Duchy of Mecklenburg
Schwerin; in which said Letters Patent is contained a proviso obliging me,
the said John Charles Christopher Raddatz, by an instrument in writing,
under my hand and seal, particularly to describe and ascertain the nature of
the said Invention, and in what manner the same is to be performed, and to
cause the same to be inrolled in His said Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said
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
John Charles Christopher Raddatz, do hereby declare the nature of the
said Invention to consist principally in using fused metal as a medium for
conveying heat to the boiler or other generator of steam used in steam engines;
as also in another improvement for regulating the heat of the said metal,
hereafter explained, and necessarily connected with the application of fused
metal for the purpose aforesaid. And in further compliance with the said
proviso, I, the said John Charles Christopher Raddatz, do hereby describe the
manner in which the said Invention may be performed by the following
description thereof, reference being had to the Drawing annexed, and the
figures and letters marked thereon, that is to say :-
DESCRIPTION OF THE DRAWING.
Figure 1 represents a longitudinal section of the said improvement.
A, A, A, A, is a large cast-iron tank or vessel with a cover. B, B, is a
quantity of an easily fusible metal or metallic mixture, that which I prefer for
the purpose being a mixture of tin and lead in about the following pro-
portions, that is to say, one part of tin and two parts of lead; B, B, must there-
fore be taken to represent fusible metal, with which it will be seen the tank or
vessel A, A, A, A, is nearly filled. The parts marked C are a series of copper
(or wrought iron) pipes or tubes, which I call generating tubes, closed at their
lower extremity and screwed at their upper ends into a brass (or cast-iron)
plate D, D, which, it will be seen, is furnished with necks on its under surface
for that purpose, while on its upper surface a hollow or groove is cut exactly
over the open ends of the generating tubes. Over this plate D, D, is screwed
a cap or cover E, E, being a plate of brass (or cast-iron) having a cor-
responding hollow or groove cut in its under surface, so that when the
plate E, E, is screwed down upon the plate D, D, a hollow space is formed
over the generating tubes, as shewn at F, F, which I call and which in fact
constitutes a steam chamber, as will be hereafter more particularly explained.
G is that part of the apparatus where the steam pipe is connected with the
steam chamber, and H is an ordinary safety valve. I is a small pipe, which
I call the feed pipe; it leads from an ordinary forcing pump, and lies along the
groove cut as before described in the plate D, D, exactly over the open ends
of the generating tubes, having small holes bored in its under side for
the emission of water, one over each of the generating tubes. J is a heat regu-
lator; but before I proceed to describe its various parts or their operation I
will describe the furnace, and mode of setting the parts already described
therein, and the method of generating steam thereby. K is a fire bar, and L

page_text: the fire. M, the ordinary door for feeding the fire, and N the door of the ash
pit. O is an air hole at one side of the furnace, to which a damper is applied,
as will be more particularly explained hereafter, when the heat regulator
comes under description. P is a partition to prevent the heat and flame
escaping into the smoke flue Q, until it has risen over the said partition,
thereby heating the upper part of the fusible metal equally with the lower.
Now, if air be admitted at O, and a fire be lighted at L, the fusible metal will
be fused or melted; then if water be injected into the generating tubes through
the small holes in the feed pipe I, by means of a forcing pump, the water so
injected will instantly be converted into steam which will collect in the steam
chamber, and thence escape into the steam pipe as occasion may require,
and for the purpose of being used in whatever engine it may be connected
with.
Having now described the mode of generating steam with the said improve-
ments I will return to the heat regulator J, which consists of a mercurial
cistern with a hollow tube J immersed therein. This cistern is to be partly
filled with mercury, then the pipe marked e is to be immersed in the fusible
metal at one end, and at the other connected with the top of the cistern in
such manner as to admit the hot air in the pipe to act upon the surface of the
mercury which it forces up the tube J in proportion as it is expanded by the
heat of the fusible metal. is a rod fixed in a float which rests on the surface
of the mercury which rises in the tube J, and rises and falls with the mercury;
and this motion of the float is made to regulate the admission of air to the air
hole O by means of a damper, as will be more particularly explained hereafter;
and I should here state, that the parts herein last described, together with the
apparatus herein-after described for connecting them with the damper, consti-
tute what I call my heat regulator.
Figure 2 is a plau of the plate D, D, or rather a plan of two plates similar
to D, D, for my metal vessel A, A, is to contain a double row of such
generating pipes as are herein-before described, or more, if required. This
Figure shews more clearly the manner in which the feed pipes I, I, lie along
the grooves in the plates D, D, D, D. In order to feed the two rows of
generating tubes the feed pipe is here shewn branching into two, but con-
nected at R, where they form a single pipe leading to the force pump.
Figure 3 is a transverse section of the said improvements, and the saine
letters which are used in Fig. 1 are used to represent the same parts in this
Figure. S is the pipe or passage which connects the two steam. chambers
together. U is the steam pipe. T is an upright or standard raised on the top
of the brickwork to support the small balance beam V; one end of the beam

page_text: is fastened to a rod W, which is connected with the damper X. This damper
covers the air hole O when let down upon it, and by excluding the air from
the fire diminishes its heat when necessary; the opposite end of the beam is
connected with the float rod f of the heat regulator. By this arrangement it
will be seen that as the heat of the fusible metal causes the rod f to rise, that
end of the beam V to which it is attached will rise also, and the other end of
the beam being consequently depressed, the damper X will close, and thus the
proper regulation of the heat will be effected without requiring the attention
of any one. In like manner if the mercury in the tube J descends, the weight
on the beam V forces that end of the beam down and the damper rises, thus
admitting a fresh supply of air to the air hole O.
Figure 4 is a side clevation of the said improvement, and is lettered with
the same letters as the other Figures, where similar parts are to be expressed.
Y is a common forcing pump, as before alluded to, fixed to the iron casing,
which is here represented as covering the whole of the masonry, by means of a
bracket, and may be worked by connecting the chain Z to some convenient
part of the engine.
Figure 5 is a section of the said heat regulator, shewing the position of the
float rod and mercury, and also the manner in which the said heat pipe leads
to the mercurial cistern.
Figure 6 is a plan of part of the heat pipe shewing the manner in which
it branches into two parts, when two rows of generating tubes are used, for
the purpose of ascertaining the heat from two different parts of the fused
metal.
Now, whereas, I have herein-before described not only such improvements
as I consider to be of the said Invention, and to constitute the said-Invention,
but also such other improvements and apparatus as I conceive are best
adapted for securing an advantageous application of the said Invention.
But, whereas, I do only claim exclusive right to the following improvements;
that is to say, first, to the metal vessel marked A, A, A, A, with the fusible or
other fused metal B, B, contained therein, as applied to the purpose of con-
veying heat to the boiler or other generator of steam connected with steam
engines; and, secondly, to the heat regulator herein-before described.
And these two said improvements being the said Invention, and to the best
of my knowledge and belief entirely new and never before used within that
part of His said Majesty's United Kingdom of Great Britain and Ireland
called England, His said Dominion of Wales, and Town of Berwick-upon-
Tweed, nor in any of His said Majesty's Colonies or Plantations abroad, I do
hereby declare this to be my Specification of the same, and that I do verily

page_text: believe that this my said Specification doth comply in all respects, fully and
without reserve or disguise, with the proviso in the said herein-before in part
recited Letters Patent contained, wherefore I do hereby claim to maintain
exclusive right and privilege to the said Invention.
In witness whereof, I, the said John Charles Christopher Raddatz, have
hereunto set my hand and seal, this Twenty-seventh day of October,
in the year of our Lord One thousand eight hundred and twenty-five.