Im- PROVEMENTS IN STEAM BOILERS
Year: 1871

page_text: LETTERS PATENT to William Blane Mack, of Philadelphia, Penn.,
United States, but at present residing at Glasgow, in the County
of Lanark, North Britain, Engineer, for the Invention of "Im-
PROVEMENTS IN STEAM BOILERS."
Sealed the 4th July 1871, and dated the 6th January 1871.
PROVISIONAL SPECIFICATION left by the said William Blane Mack
at the Office of the Commissioners of Patents, with his Petition,
on the 6th January 1871.
I, WILLIAM BLANE MACK, of Philadelphia, Penn., United States, but
at present residing at Glasgow, in the County of Lanark, North
Britain, Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN STEAM BOILERS," to be as follows, that is to
say :-
This Invention has for its object by an improved construction securing
a vigorous circulation of the water to render steam boilers more efficient
and less liable to derangement than heretofore. A boiler made with
the improvements comprises two parts, an upper liorizontal (or more or.

page_text: less inclined) cylindrical shell and a series of lower tubes parallel or
nearly so to the shell above. The tubes have the water inside of them,
and are disposed so as to present the form of an arch in cross section
the space within and beneath the series of tubes being occupied by the
furnace and flue leading therefrom, and which with the tube are enclosed
by arched brickwork. The flue after leaving the space beneath the
tubes may be led along the bottom and sides of the upper cylindrical
shell, and thence to the chimney. The tubes are fixed into two arch-
shaped castings one at each end, and each end casting is formed with
spaces putting the tubes in communication with cach other in pairs.
The two lowest tubes, one on each side of the series are put in com-
munication by branch pipes with the upper cylindrical shell at one
end, whilst the two highest or middle tubes are similarly put in
communication with the upper shell at the other end. The action
of the fire causes the water to circulate vigorously in two streams, first
traversing the lowest tubes and returning backwards and forwards
along the other ones in succession to the highest, whence the streams
re-enter the upper shell. The tubes may be fixed in their end castings
in various ways the joints being if necessary protected from the direct
action of the fire by brickwork. The plan of fixing them preferred is
by screwing in each tube at one end, and connecting the other end by
flanges and bolts, or both ends may be fixed by flanges and bolts, in
which case any single tube may be removed and replaced without
disturbing the others.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said William Blane Mack in the Great Seal Patent Office
on the 5th July 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BLANE MACK, of Philadelphia, Penn., United States, but at present
residing at Glasgow, in the County of Lanark, North Britain, Engineer, 3
send greeting.
WHEREAS Her most Excellent, Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of January, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign; did, for Herself, Her heirs and successors,. 3.

page_text: give and grant unto me, the said William Blane Mack, Her special
licence that I, the said William Blane Mack, my executors, admini-
strators, and assigns, or such others as I, the said William Blane Mack,
my executors, 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 "IMPROVEMENTS
IN STEAM BOILERS," upon the condition (amongst others) that I, the said
William Blane Mack, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and scals, 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 William Blanc Mack, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement in writing, reference being had to the
accompanying Drawings, that is to say :-
My said Invention has for its object by an improved construction
securing a vigorous circulation of the water to render steam boilers
imore efficient and less liable to derangement than heretofore.
And in order that, my said Invention and the manner of performing
the same may be properly understood I hereunto append a Sheet of
explanatory Drawings to be herein-after referred to and representing
a steam boiler as made with my improvements.
Figure 1 is a sectional elevation of the front end, and Figure 2 is a
sectional side elevation; whilst Figure 3 is a back end elevation of a
part of the boiler. My improved boiler comprises two parts, an upper
horizontal (or more or less inclined) cylindrical shell 11, and a series
of lower tubes, numbered 1 to 10, and parallel or nearly so to the
shell 11 above. The tubes 1 to 10 have the water inside of them and
are disposed so as to present the form of an arch in cross section, the
space within and beneath the series of tubes being occupied by the
furnace 12, and flue 13, leading therefrom, and which with the tubes
are enclosed by arched brickwork. The flue after leaving the tubes
may be led along the bottom and sides of the upper cylindrical shell 11,

page_text: or as shown, through a flue tube extending through the boiler and
thence by side flues to the chimney. The tubes 1 to 10 are fixed into
two arch-shaped castings 14, 15, one at each end, and each end casting
is formed with spaces separated by partitions, and putting the tubes
into communication with each other in pairs. The two lowest tubes 1, 10,
one on each side of the series, are put in communication by branch
pipes 16 with the bottom of the upper cylindrical shell 11 at one end,
whilst the two highest or middle tubes 5, 6, are at the other end
similarly put in communication by a pipe 17 with a part of the upper
shell 11 near the water line. The action of the fire causes the water
to circulate vigorously in two streams, as indicated by the arrows, first
traversing the lowest tubes 1, 10, and returning backwards and forwards
along the other ones in succession to the highest 5, 6; whence the
streams uniting re-enter the upper shell 11 by the pipe 17. The tubes
may be fixed in their end casings 14, 15, in various ways, the joints being
if necessary protected from the direct action of the fire by brick work. The
plan of fixing them which I prefer, and which is shown in the Drawings,
is by screwing in each tube at one end, and connecting the other end
by flanges and bolts, or both ends may be fixed by flanges and bolts,
in which case any single tube may be removed and replaced without
disturbing the others.
Having thus particularly described my said Invention, and the manner
in which the same is to be performed, I have to state that I do not
restrict myself to the precise details herein described or delineated, but
that what I believe to be novel and original and claim as the Invention
secured to me by the herein-before in part recited Letters Patent is, the
constructing of steam boilers with a series of tubes disposed in the form of
an arch below the main body, and arranged to cause a vigorous circulation
of the water, substantially in the manner herein-before described.
In witness whereof, I, the said William Blane Mack, have here-
unto set my hand and seal, this 4th day of July, in the year
of our Lord One thousand eight hundred and seventy-one.