Improvements in the Manufacture or Treatment of Aneroid Barometers with a view to Prevent or Reduce Errors or Variations in their Indications.
Year: 1892

page_text: Date of Application, 11th June, 1892
Complete Specification Left, 6th Mar., 1893-Accepted, 10th June, 1893
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture or Treatment of Aneroid
Barometers with a view to Prevent or Reduce Errors or
Variations in their Indications.
We, EDWARD WHYMPER, of Surrey House, Victoria Embankment, Gentleman,
and JAMES JOSEPH HICKS, of 8 Hatton Garden, Meteorological Instrument
Manufacturer, both in the County of Middlesex, do hereby declare the nature of
this invention to be as follows:-
It has been found that aneroid barometers as hitherto supplied to the public
have been subject to material errors or variations in their indications on being
submitted to low pressures for a considerable period, and such errors or variations
are found equally to exist in such barometers whether such low pressures have
been consequent on different altitudes or have been artificially created.
Now we have found that the cause of these errors or variations lies in the fact
that the metals of which aneroid barometers are made, are in a condition of
unequal tension of some parts in relation to others, the consequence being that,
when subjected for a considerable period to low pressures, some or other member
of the barometer, or some portion or portions of one or more members thereof,
have been strained or 66
fatigued," thereby producing the errors or variations
above referred to.
In order to remedy the above evil we submit the barometer, when completely
manufactured and adjusted, to an annealing process continued for a long period at
such a temperature as will not melt or soften the solder used in the construction or
in any way injure any part of the barometer.
Or such annealing process may be applied to the various important members
when they are individually completed but separate from each other.
This annealing process is preferably conducted at as high a temperature as
possible consistent with the above conditions; we therefore, in order to enable
the barometer to endure the desired temperature, employ in the construction of
aneroid barometers, a solder which will not be affected by the high temperature
employed in the annealing process.
We preferably conduct the annealing process in a heated chamber so constructed
as to protect the contents from the access of cold air. This may be obtained by
the use of a double walled chamber with space between the walls, or the aneroids,
or the principal members thereof, may be embedded and annealed in refractory
material, so as to exclude air therefrom.
We have found that a temperature of from 400° to 500° is very suitable for the
annealing process, and that the latter should be continued for a period of from
10 to 16 days, but we do not confine ourselves to these temperatures or periods
of time.
Dated this 11th day of June 1892.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture or Treatment of Aneroid
Barometers with a view to Prevent or Reduce Errors or
Variations in their Indications.
We, EDWARD WHYMPER of Surrey House, Victoria Embankment, Artist and
JAMES JOSEPH HICKS of 8 Hatton Garden, Meteorological Instrument Manu-
facturer, both in the County of Middlesex, 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 :-
It has been found that aneroid barometers as hitherto supplied to the public
have been subject to material errors or variations in their indications after having
been submitted to low pressures for a considerable period and such errors or
variations are found equally to exist in such barometers whether such low
pressures have been consequent on different altitudes or have been artificially
created.
Now we have found that the cause of these errors or variations lies in a great
measure if not entirely in the fact that the metals of which aneroid barometers are
made, are in a condition of unequal tension of some parts in relation to others the
consequence being that when subjected for a considerable period to low pressures
some or other member of the barometer or some portion or portions of one or more
members thereof have been strained or "fatigued" thereby producing the errors
or variations above referred to when the barometer is afterwards subjected to
higher pressures.
In order as far as possible to remedy the above evil we submit the barometer
when completely manufactured and adjusted to give the range of scale required to
an annealing process continued for a long period at a high temperature but taking
care that it is not so high as to melt or soften the solder used in the construction or
in any way injure any part of the barometer.
Or such annealing process may be applied to the various important members of
the barometer when they are individually completed but before they are combined
into a barometer.
This annealing process is preferably conducted at as high a temperature as
possible consistent with the above conditions, we therefore in order to enable the
barometer to endure the desired temperature employ in the construction of aneroid
barometers a solder which will not be affected by the high temperature employed
in the annealing process.
f
A solder composed of four parts lead and one part tin answers these conditions.
We preferably conduct the annealing process in a heated chamber so constructed
as to protect the contents from the access of cold air. This may be obtained by
the use of a double walled chamber with space between the walls or the aneroids
or the principal members thereof may be embedded and annealed in refractory
material so as to exclude air therefrom.
We have found that a temperature of from 400° to 500° Fahrenheit is very
suitable for the annealing process and that the latter should be continued for a
period of from ten to sixteen days but we do not confine ourselves to these
temperatures or periods of time.
After having been annealed as above described the scale of the barometer is
pointed or laid off and then divided in the ordinary manner.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is.
1. The improvements in the manufacture of treatment of aneroid barometers
consisting in subjecting the same, after having been completely manufactured

page_text: and adjusted to give the range of scale required, to an annealing process
continued for a long period at a high temperature substantially as and for the
purpose stated.
2. The improvements in the manufacture or treatment of aneroid barometers
consisting in subjecting the various important members thereof, when individually
completely manufactured but not yet combined in a barometer, to an annealing
process continued for a long period at a high temperature substantially as and
for the purpose stated.
3. The improvements in the manufacture or treatment of aneroid barometers
substantially as herein described and for the purpose stated.
Dated this 6th day of March 1893.
EDWARD WHYMPER,
JAMES JOSEPH HICKS,
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.