AN IMPROVED STEAM GUAGE
Year: 1861

page_text: LETTERS PATENT to George Searby, of Threadneedle Street, City of
London, Merchant, for the Invention of "AN IMPROVED STEAM GUAGE."
Sealed the 7th May 1861, and dated the 14th February 1861.
PROVISIONAL SPECIFICATION left by the said George Searby at the
Office of the Commissioners of Patents, with his Petition, on the 14th
February 1861.
I, GEORGE SEARBY, of Threadneedle Street, City of London, Merchant,
do hereby declare the nature of the said Invention for "AN IMPROVED STEAM
GUAGE," to be as follows, that is to say:-
I take a series of short tubes and connect them in pairs at their tops and
bottoms, in such a way that the series forms a continuous communication or
continuous undulating tube, having an open mouth at each of the extreme
tubes of the series. The lower portions of each tube I fill with mercury, the
upper portions with water or any other lighter liquid, preferably coloured. The
whole I mount in a box or attach to a frame. When used, the one open ex-
tremity at one end is attached to the steam pipe, the other open to the atmo-
sphere, or it may have a float or other well-known indicator upon it by which
the difference in the level of the mercury is indicated. Should it be required
to use the guage as a measure of a vacuum in a condensor, then the action
will be reversed, the open end of the first tube in the series will be put in com-

page_text: munication with the interior of the vacuum vessel, and the outer end being
either closed and a perfect vacuum formed, or open to the atmosphere, in
13
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Searby in the Great Seal Patent Office on the
14th August 1861.
.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
SEARBY, of Threadneedle Street, City of London, Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of February, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto I, the
Baid George Searby, Her special licence that I, the said George Searby, my
executors, administrators, and assigns, or such others as I, the said George
Searby, 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 "AN IMPROVED STEAM GAUGE," upon
the condition (amongst others) that I, the said George Searby, 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 George Searby, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say :-
I take a series of shut tubes and connect them in pairs at the tops and
bottoms, or by a curved junction, or in any other way, so as to form a con-
tinuous equally convoluted tubular communication; or instead of taking a
series of tubes I take a single tube bent into single or double convolutions,
that is, cither of a gridiron shape or of spiral convolutions, the object being to
form a long tubular communication, and at the same time to occupy a small

page_text: longitudinal or vertical space. Each end of the tube or tubular communica-
tion is open in the front and in a line about the medial plane of the tubes, and
in each alternate leg I form a small orifice; through this orifice I introduce
mercury and distilled or boiled water, in such a way that the mercury will fill ·
the lower parts of the tubes and the distilled or boiled water the upper, and
thus exclude every portion of air. The mode in which I effect the introduction
of these fluids, which said mode is the peculiarity of my Invention, is as
follows:-I use a trough, within which I place mercury and water, the former
occupying the lower portion, the latter the upper. I now take the convoluted
tube and submerge it under the water, which, entering at the small orifices
before mentioned, fills wholly the tubes, driving out the air, still retaining the
tube under the water. I place it vertically within the mercury at the bottom
of the trough; the heavier liquid displaces the lighter. I now raise it up out
of the mercury and hold it vertically under the water; in this state I either
close the orifices with screws or cover the whole with a plate firmly attached.
In order to illustrate more fully my Invention, I have appended the follow-
ing Drawings to this Specification, which are, however, intended to be merely
illustrative of the process I adopt in filling the said tubular gauges.
Figure 1 is a sectional elevation of the gauge constructed of a tube in one
series of convolutions.
Figure 2 is another view of same in spiral convolutions.
Figure 3 is one made of a series of tubes.
Figure 4 is a cross section of Figure 2.
Figure 5 is an enlarged sectional view shewing the way in which the
orifices a, a, a, are closed.
Figure 6 is a sectional view of the trough.
The operation of introducing, filling, and closing is effected as follows:-The
gauge of any of the forms shewn is placed within the trough underneath the
water (not the mercury, which is indicated by the blue lines x, y, as the sepa-
ration between the mercury and water); the water entering through the
orifices a, a, fills it wholly without removing from the water; it is plunged ver-
tically into the mercury, which displaces the water to the depth of the orifices;
in this state it is removed from the mercury, but still kept under the water,
and being suspended or fixed, the orifices are closed up either by means of a
screw or plug, or by covering them with a plate, as shewn in Figure 5.
Having now fully described the nature of my Invention, and how the same
is performed, I wish it understood that I do not claim as my Invention the
peculiar form of convoluted gauges shewn, as these have been made before, but
from the difficulty of filling and closing them so as to exclude the air they have

page_text: hitherto been useless; but what I do claim and wish secured to me by the
before in part recited Letters Patent is, the herewithin described method of
introducing and filling partly with mercury and partly with distilled or boiled
water, or other lighter liquid, gauges for indicating steam or vacuum pressure,
having forms similar to those shewn and herewithin described, as composed of
a convoluted tube or series of tubes, and the methods of closing the same, as
substantially set forth in this Specification and illustrated in the accompanying
Drawings.
In witness whereof, I, the said George Searby, have hereunto set my
hand and seal, this Fourteenth day of August, in the year of our Lord
One thousand eight hundred and sixty-one.
GEORGE SEARBY. (L.B.)