IMPROVEMENTS IN STEAM BOILERS
Year: 1872

page_text: LETTERS PATENT to James Henry Mills, of College Street, in the
City of London, Gentleman, for the Invention of "IMPROVEMENTS IN
STEAM BOILERS."
Sealed the 13th August 1872, and dated the 8th April 1872.
PROVISIONAL SPECIFICATION left by the said James Henry Mills
at the Office of the Commissioners of Patents, with his Petition,
on the 8th April 1872.
I, JAMES HENRY MILLS, of College Street, in the City of London,
Gentleman, do hereby declare the nature of the said Invention for
“IMPROVEMENTS IN STEAM BOILERS," to be as follows (that is to say):
This Invention consists of an improved construction of boiler especially
applicable where small or medium power only is required, the boiler
being constructed complete in itself without the furnace, so that either
gas, coke, or other fuel may be used, as circumstances may render
desirable, and as more fully herein-after described.
The outer shell of the boiler I make of any well known or approved
shape, though for convenience and economy of construction I prefer

page_text: that the bottom should be flat, or nearly so. From this bottom plate,
and extending upwards within the boiler, I fix any required number
of vertical tubes, their upper ends terminating in the bottom plate of a
box or chamber, to be situated within the boiler for the purpose of
giving increased heating surface, and at a sufficient distance from the
top of the said boiler to allow of its being well covered with water and
to leave sufficient steam room above. From this inner chamber one
or more flues are carried through the outer shell of the boiler, but
I prefer two, one at each end, so as to maintain a better and more
regular draft. The outer shell of the boiler is then provided with a
heat conserving jacket, not touching but with a space of some inches
between it and the boiler, to which it is connected in any convenient
manner, and when desired may be carried to a sufficient depth below
the boiler to serve as a convenient stand or substitute for setting, so as
to leave sufficient room below the boiler for the furnace or gas stove, as
the case may be. This space round the outer shell of the boiler may
be made to communicate or not with the flues as found desirable, but
in any case it provides for a coating of hot air around the whole of
the boiler, thus greatly economising the heat. The boiler thus con-
structed may either be set in the usual manner, and used with any
suitable kind of furnace as found desirable, or may be heated by gas
applied to its, under surface in any convenient manner.
'
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Henry Mills in the Great Seal Patent
Office on the 8th October 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HENRY MILLS, of College Street, in the City of London, Gentleman;
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of April, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said James Henry Mills, Her spécial license
that I, the said James Henry Mills, my executors, administrators,

page_text: '
P
and assigns, or such others as I, the said James Henry Mills, my exc-
cutors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the
term therein expressed, should' and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN STEAM BOILERS," upon the condition (amongst others) that I,
the said James Henry Mills, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said 'James Henry Mills, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
This Invention relates to an improved construction of steam boiler
specially applicable where small or medium power only is required, it
being constructed complete in itself without the furnace so that either
gas, coal, coke, or other fuel may be used, as circumstances may render
desirable..
And in order that my Invention may be clearly understood and
readily carried into effect, I will proceed to describe the same with the
aid of the accompanying Drawings, reference being had to the letters
and figures marked thereon, and in which Figures 1 to 4 inclusive shew
my improvements applied as a horizontal boiler, and Figures 5 to 9
inclusive as a vertical.
Figure 1 is a longitudinal vertical section taken at the centre line of
the boiler; Figure 2, a transverse vertical section taken also at the
centre line; Figure 3, a horizontal section taken at the line A, B,
Figure 1; and Figure 4, a sectional part view more fully herein-after
described; Figure 5 is a vertical section taken at the centre line and
shewing the back half of the boiler; Figure 6, a transverse vertical
section taken also at the centre line; Figure 7, a plan taken at the line
C, D, Figure 5; and Figures 8 and 9 part views more fully herein-after

page_text: .
described. In each Figure the same letter wherever it occurs indicates
the same or corresponding parts.
Both forms of boiler herein shewn are constructed specially for being
heated by gas as herein-after described.
The outer shell of the boiler (E) I make of any well known or approved
shape, though for convenience and economy of construction I prefer the
forms shewn in the accompanying Drawings. From the bottom plate of
the boiler, and extending upwards within the same, I fix any required
number of vertical tubes (F), their upper ends terminating in the bottom
plate of a box or chamber (G) situated within the boiler for the pur-
pose of giving increased heating surface, and at a sufficient distance
from the top thereof to allow of its being well covered with the
water and at the same time leaving sufficient steam room above.. From
this inner chamber one or more flues or funnels (H) are carried through
the outer shell of the boiler, but for horizontal boilers I prefer two, as
shewn, as they maintain a better and more regular draught. The outer
shell of the boiler is provided with a heat conserving jacket (I) so made
and applied as to leave a space of some inches between it and the
boiler, to which it is connected in any convenient and suitable manner,
and is carried to a sufficient depth below the bottom of the boiler to
cover in the gas stove or furnace to be employed for generating the
steam. It may also be made to serve as a stand for the boiler, but I
prefer for this purpose a separate frame (J). The gas stove or furnace
is slid in underneath the boiler through an opening (K) made for that
purpose. The mouth of this opening as constructed for the vertical
boiler is shewn in detail at Figure 8. The space between the jacket (I)
and the boiler may be either completely closed in, as shewn at
Figures 1, 2, 5, and 6, or open, as shewn at Figures 4 and 9.
In order to utilize the heat as much as possible I construct on the top
of the boiler (see Figures 5 and 6) a chamber (L) in which the feed
water is kept for some time before being forced into the boiler, by which
means it is heated before its admission therein, and where it is intro-
duced at or near the bottom through a suitable connecting pipe (M.)
This chamber, although shewn in the accompanying Drawings as applied
only to the vertical boiler, is equally applicable to the horizontal.
Where any of the fittings of the boiler have to pass through the said
jacket (1) the joint when so desired is rendered tight by felting, corking,
or other suitable and well known means.

page_text: Although the two forms of boilers herein described are constructed so
that an ordinary gas stove may be employed in conjunction therewith
for getting up steam, yet I prefer for that purpose the gas stove or heat
generator for which Letters Patent have been granted to me bearing
date the 8th April 1872, and numbered 1038, as that generator will be
found specially applicable; or instead of any gas stove either form of
boiler herein described may have constructed in connection with it any
suitable or well known make of furnace in which any suitable or desired
description of fuel may be used.
Having therefore thus particularly described and ascertained the
nature of this my said Invention, and the manner in which the same is
to or may be performed, I would observe in conclusion that I do not
confine myself to the precise details herein set forth, as the same may
be modified in various ways without departing from the main features of
my Invention; but what I claim as my Invention, and desire to secure
by the herein-before in part recited Letters Patent is,―
First. The said vertical tubes (F) and chamber (G) when used in
connection with one another and formed and used or applied, sub-
stantially as and for the purpose or purposes herein-before set forth and
described.
Second. The heat conserving jacket (I) formed and used or applied
substantially as and for the purpose or purposes herein-before set forth
and described.
Third. The chamber (L) for heating the feed water formed and used
or applied, substantially as and for the purpose or purposes herein-before
set forth and described.
In witness whereof, I, the said James Henry Mills, have hereunto
set my hand and seal, this Eighth day of October, in the year of
our Lord One thousand eight hundred and seventy-two.
Witness,
JOHN W. GRAY, C.E.,
Patent Agent,
23, Billiter Street, E.C.
JAS. HY. MILLS. (L.S.)