IMPROVEMENTS IN WET GAS METERS."
Year: 1858

page_text: LETTERS PATENT to William Esson, of Cheltenham, in the County of
Gloucester, Engineer, for the Invention of "IMPROVEMENTS IN WET GAS
METERS."
PROVISIONAL SPECIFICATION left by the said William Esson at the
Office of the Commissioners of Patents, with his Petition, on the 27th
August 1858.
I, WILLIAN ESSON, of Cheltenham, in the County of Gloucester, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
WET GAS METERS," to be as follows:-
This Invention relates to a peculiar system or mode of maintaining the
proper water level in wet gas meters by compensating for the evaporation or
other loss of the water in the meter.
According to this Invention, the upper part of the meter is furnished with
an air-tight water supply tank, which communicates with the measuring
chamber by means of a feed pipe dipping into the water in the front part of
the measuring chamber, so as to be always sealed. An air pipe also opens
from the supply tank, its lower mouth or orifice coinciding, or nearly so, with

page_text: the proper water level. The water is supplied to the tank by a supply pipe,
which is kept constantly sealed. As the level of the water in the meter
descends below its proper level, by reason of evaporation or other loss, it leaves
exposed the lower orifice of the air pipe, and allows the water in the upper
tank to descend until the air pipe is sealed by the water in the meter regaining
its proper level.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Esson in the Great Seal Patent Office on the 25th
February 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
Esson, of Cheltenham, in the County of Gloucester, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of August, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-second year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Esson, Her special licence that I, the said William Esson,
my executors, administrators, and assigns, or such others as I, the said William
Esson, my executors, administrators, or 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 WET GAS METERS,"
upon the condition (amongst others) that I, the said William Esson, by an
instrument in writing under my hand and seal, 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 Esson, 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, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say:-
My said Invention relates to a peculiar system or mode of maintaining the

page_text: proper water level in wet gas meters by compensating for the evaporation or
other loss of the water in the meter.
According to this Invention, the upper part of the meter is furnished with
an air-tight water supply tank, which communicates with the measuring
chamber by means of a feed or supply pipe, so disposed as to be always
sealed. The supply tank is provided with an air pipe, the lower mouth or
orifice of which coincides, or nearly so, with the proper water level, and a float
is contained therein connected with the ordinary gas valve, for the purpose of
shutting off the gas when the tank is empty or the water therein too low.
The water is supplied to the tank by a supply pipe, which is kept constantly
sealed. When the water in the meter descends below its proper level, by reason
of evaporation or other loss, it leaves exposed the lower orifice of the air pipe,
and allows the gas to ascend therethrough, and the water in the upper tank to
descend through a pipe for that purpose until the air pipe is sealed again by
the water in the meter regaining its proper level.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts throughout all the
Figures.
Figure 1 of the accompanying Sheet of Drawings represents a vertical
section taken along the line 1-2, in Figure 8, of a wet gas meter fitted with
my compensating apparatus; Figure 2 is a section along the line 3-4 in
Figure 1; and Figure 3 is a horizontal section of the same, taken along the
line 5-6 in Figure 1. A is the front chamber, and B the waste box,
arranged as in an ordinary "low spouted" wet gas meter, with the exception
that the float C is removed from its usual position under the valve, and placed
in the reservoir or water supply tank D. This tank is supplied with water by
means of the feed pipe E, which is kept constantly sealed by the water in the
surrounding closed pipe F, within which the feed pipe is enclosed.
sufficient opening or space is left at the top of the pipe F, to allow the feed
water when poured in at E to flow over the lip or edge of the pipe F into the
supply tank D. An air pipe G forms a communication between the front
chamber of the meter and the supply tank. The use of this air pipe in com-
bination with the supply tank constitutes the essential feature of my Inven-
tion, and therefore I do not confine myself to the particular arrangement
shewn in the Drawings, wherein this pipe is represented as being soldered to
and forming part of the outer feed pipe F, although I prefer so to apply it as
A

page_text: it will be obvious upon explaining its action that it might be applied in other
parts of the tank and meter. H is a pipe which supplies, when necessary,
from the tank D the requisite quantity of water to compensate for loss by
evaporation or otherwise to the front chamber A of the meter. The tank D is
made air-tight, and consequently no water can flow down the pipe H until air
or gas is allowed to enter the tank, When the level of the water in the
meter falls below its proper height, and below the lower mouth of the air
pipe, it will unseal that pipe, and gas will enter the water tank, at the same
time allowing a supply of water to descend the pipe H into the front chamber,
and raise the water in the meter to the proper level, whereupon the air pipe
will be sealed again, and the further supply stopped until again required by
the descent of the water below the proper level.
By placing the float C within the supply tank in lieu of in the meter, com-
plete security is given to the gas companies, as the emptying of the supply
tank or reservoir will close the gas valve. The float is submerged some
distance below the surface of the water in the tank, and consequently will not
act upon the gas valve I until the tank is nearly empty. For convenience
sake, I pass the float spindle through the supply pipe H, connecting it with
the valve spindle by a connecting arm K.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as variations may be made therefrom without deviating
from the principles or main features of my said Invention; and also that I
am aware that it has been previously proposed to compensate for the loss of
water by evaporation or otherwise in wet gas meters, by placing a supply tank
or reservoir above the meter, and allowing a supply of water to enter the
meter through a supply pipe, which when unsealed allows the gas or air to
pass up therethrough into the tank, and a supply of water to pass down the
same pipe; but what I consider to be novel and original, and therefore claim
as the Invention secured to me by the herein-before in part recited Letters
Patent is,
First, the general construction and arrangement of compensating wet gas
meters, as herein-before described.
Second, the peculiar system or mode of compensating for the loss of water
occasioned in wet gas meters by evaporation or otherwise, as herein-before
described.

page_text: Third, the application and use to and in wet gas meters of a separate air-
tight water supply tank combined with an air or gas pipe, and with a separate
and distinct water supply pipe, both pipes dipping into the water in the front
chamber, or in any other convenient portion of the meter, in the manner and
for the purpose herein-before described.
In witness whereof, I, the said William Esson, have hereunto set my
hand and seal, this Twenty-third day of February, One thousand
eight hundred and fifty-nine.
WILLIAM ESSON. (L.S.)