IMPROVEMENTS IN APPARATUS FOR HATCHING EGGS BY ARTIFICIAL HEAT, WHICH IMPROVEMENTS ARE IN PART APPLICABLE TO OTHER PURPOSES."
Year: 1881

page_text: LETTERS PATENT to Charles Edward Hearson, of No. 115, Southwark Street,
in the County of Surrey, Engineer, for an Invention of "IMPROVEMENTS IN
APPARATUS FOR HATCHING EGGS BY ARTIFICIAL HEAT, WHICH IMPROVEMENTS
ARE IN PART APPLICABLE TO OTHER PURPOSES."
PROVISIONAL SPECIFICATION left by the said Charles Edward Hearson at
the Office of the Commissioners of Patents on the 24th November 1881.
CHARLES EDWARD HEARSON, of No. 115, Southwark Street, in the County of
Surrey, Engineer. "IMPROVEMENTS IN APPARATUS FOR HATCHING EGGS BY
ARTIFICIAL HEAT, WHICH IMPROVEMENTS ARE IN PART APPLICABLE TO OTHER
PURPOSES."
My Invention consists first of the improvements hereinafter described, by which
an equable or nearly equable temperature is automatically maintained within
incubators or apparatus for hatching eggs by artificial heat.
An incubator as ordinarily constructed consists of a box or chest in the upper
part of which is a tank or vessel for containing hot water, and in the lower part a
drawer for containing the eggs to be hatched, the said eggs being hatched by the
heat radiated from the underside of the hot water tank. In case this apparatus is
attended by the disadvantage that the water gradually loses its heat, and requires
to be removed and replaced by freshly heated water from time to time, and the
eggs are consequently subjected to injurious variations of temperature.
According to my Invention I heat the water in the tank by means of a gas
flame or other convenient and suitable source of artificial heat, and automatically
regulate the amount of heat conveyed to the water by means of apparatus actuated
by the vaporization and condensation of a liquid which boils at about the same
temperature as that at which the eggs should be kept, the vaporization of the said
liquid causing the heat to be diverted from the water tank, and the condensation
of the said liquid causing the heat to be conveyed thereto.
In carrying out my said Invention I arrange a flue or tube in the water tank,
the ends of the said flue or tube passing through and projecting from the sides of

page_text: the chest or case of the incubator, and I arrange a gas burner in connection with
the said flue so that the flame of a jet of gas issuing from the burner shall cause a
current of heated air to pass through the flue, the water in the tank being thereby
heated. In order to regulate the quantity of heated air passing through the said
flue, I arrange beneath the water tank a hermetically scaled case of thin metal or
other suitablo material, the said case being filled with a liquid which boils at a
temperature of about 107 degrees Fahrenheit, and being so formed as to be capable
of being expanded by pressure from within, and of being caused to collapse by
pressure from without; and I connect the said case by means of a rod and lever or
other suitable mechanisin with a valve or damper by varying the position of which
the passage of heated air through the flue may be regulated, or entirely shut off or
diverted.
The action of this apparatus is as follows:-When the water in the tank has
been raised to the necessary temperature by the heated air passing through the flue
the liquid in the hermetically sealed case boils, and the said case is thereby
expanded, its expansion causing the position of the damper to be so altered as to
lessen the quantity of heated air passing through the flue or to entirely divert it,
the said damper remaining in the position to which it has been brought by the
expansion of the hermetically scaled case until the temperature of the water
has slightly fallen, when the liquid in the said case condenses and allows it to
collapse, thereby altering the position of the valve or damper so as to cause the air
heated by the gas flame again to pass through the flue in the water tank.
By my improvements the interior of the incubator is kept at a practically even
temperature, the increase of heat required to boil the liquid in the hermetically
sealed case and the decrease of heat required to condense the said liquid being only
a fraction of a degree.
My Invention consists further of the apparatus herein after described for
facilitating the examination of the eggs under operation. I arrange in a con-
venient position with respect to the flame used for heating the incubator a plate
having in it a hole of a size rather larger than that of an egg, and I arrange a
reflector below the said plate in such a position that the light of the flame shall be
directed upward through the said hole over which the egg to be examined is
placed, and supported by a plate having in it an aperture of a suitable size.
That part of my Invention which consists in varying the position of a valve or
damper by mechanism connected with and actuated by the expansion and
contraction of a hermetically sealed case containing a liquid, is applicable to the
regulation of heat for purposes other than that to which I have described it as
applied.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Edward Hearson in the Great Seal Patent Office on the
23rd May 1882.
CHARLES EDWARD HEARSON, of No. 115, Southwark Street, in the County of
Surrey, Engineer. "IMPROVEMENTS IN APPARATUS FOR HATCHING EGGS BY
ARTIFICIAL HEAT, WHICH IMPROVEMENTS ARE IN PART APPLICABLE TO OTHER
PURPOSES."
My Invention consists of the improvements herein after described, by which an
equable or nearly equable temperature is automatically maintained within incu-
bators or apparatus for hatching eggs by artificial heat.
An incubator as ordinarily constructed consists of a box or chest, in the upper
part of which is a tank or vessel for containing hot water, and in the lower part a
drawer for containing the eggs to be hatched, the said eggs being hatched by the
heat radiated from the underside of the hot water tank. In use this apparatus is
attended by the disadvantage that the water gradually loses its heat, and requires
to be removed and replaced by freshly heated water from time to time, and the
eggs are consequently subjected to injurious variations of temperature.
According to my Invention I heat the water in the tank by means of a gas
flame or other convenient and suitable source of artificial heat, and automatically
regulate the amount of heat conveyed to the water by means of apparatus actuated
by the vaporization and condensation of a liquid which boils at about the same
temperature as that which the eggs should be kept, the vaporization of the said
liquid causing the heat to be diverted from the water tank, and the condensation
of the said liquid causing the heat to pass thereto.
In carrying out my Invention I arrange a flue or tube in the water tank, the
ends of the said flue or tube passing through and projecting from the sides of the
chest or case of the incubator, and I arrange a lamp or gas burner in connection
with the said flue, so that the flame of the lamp or of a jet of gas issuing from the
burner shall cause a current of heated air to pass through the flue, the water in
the tank being thereby heated. In order to regulate the quantity of heated air
passing through the said flue arrange beneath the water tank a hermetically
sealed case of thin metal or other suitable material, the said case being filled with
or containing a piece of absorbent fabric saturated with a liquid which boils at a
temperature of about 107 degrees Fahrenheit, and being so formed as to be capable
of being expanded by pressure from within and of being caused to collapse by
pressure from without, and I connect the said caso by means of a rod and lever or
other suitable mechanism with a valve or damper, by varying the position of which
the passage of heated air through the flue may be regulated or entirely shut off or
diverted.
Figure 1 of the accompanying Drawings is a side elevation, Figure 2 is a plan,
and Figure 3 is a section (taken on the line A, Figure 2) of an incubator or
apparatus for hatching eggs by artificial heat, to which my improvements are
applied. Figures 4 and 5 are details of the said apparatus hereinafter referred to.
The same letters and figures of reference indicate the same parts in the several
Figures of the Drawings. a is the case of the incubator; b is the tank or water
vessel; b' is a thermometer, by which the heat of the water in the said vessel may
be ascertained; and 6 is a gauge glass for showing the height of the water in the
said vessel; c is the drawer, in which the eggs to be hatched aro placed, the said
eggs (marked d in Figure 3 of the Drawings) being supported by a perforated
tray c¹, through the perforations in which air passes, the air entering the apparatus

page_text: by the aperture e and passing out by apertures in the front and back of the case,
two of which apertures are shown in Figure 3, and marked f, f. The course of the
air is indicated by arrows in Figure 3. g is the usual packing of sawdust or
other imperfect conductor of heat, and h is the water tray for moistening the air
as it enters the incubator; i is the lamp, by which the water in the tank b is
heated. The said lamp is contained in a casing j, and is provided with a chimney k
furnished with a valve or damper 7. m is the fluo passing through the water
vessel or tank a, one end of which flue is connected to the chimney of the lamp i,
the other end being open to the atmosphere. n' is the hermetically sealed metal
case or capsule supported by brackets o, o, beneath the water vessel b, which case
or capsule is shown separately in plan, edge view, and section in Figure 4, and
consists of two plates of metal n, n, soldered together at their edges, and
hermetically enclosing a piece of absorbent fabric (such as blotting paper) saturated
with gazoline or any liquid which boils at the temperature at which the interior
of the apparatus is required to be kept. The mechanism by which the expansion
and collapsion of the case or capsule n' is caused to actuate the valve or damper
consists of a rod 9 passing freely through a tube p secured near its upper and lower
ends in the top and bottom respectively of the water vessel b, which rod q bears at
its upper end against a screw working in a socket 7+ formed on a lever 7¹, which
lever is formed on an axis which works on centres s¹, 8¹, carried by a standard t
mounted on the top of the case a. The said axis has also formed on it another
lever, to which is affixed a rod 70, which constitutes a prolongation of the said
lever, and carries a sliding weight, and has formed at its free end a hook 78, to
which the damper of the chimney & is suspended.
This arrangement acts as follows:-The whole of the heat from the flame of the
lamp passes through the tube or flue m until the water in the vessel b is
sufficiently heated to raise the temperature of the interior of the apparatus to the
degree at which the liquid in the case or capsule n' boils. When the said liquid
boils it expands the capsule n' and the rod q resting on it is consequently raised
and raises the levers 71, 72, and the damper 2 of the chimney h, which chimney
being now open the current of heated air from the lamp passes through it to the
atmosphere instead of passing through the flue m and continues to pass through
the said chimney until the water has cooled sufficiently to allow the capsule n¹ to
collapse, when the rod 9 and levers 71, 73, descend and the chimney is closed and
remains closed until the current of heated air from the lamp passing through the
tube or flue m has again raised the temperature of the water to the degree
necessary to expand the capsule n' and again divert the heat from the water vessel
b. A practically even temperature is thus automatically maintained within the
incubator, the variation of temperature being but a fraction of a degree.
is
The method of using the apparatus herein before described is as follows:-The
egg drawer c and water tray h are removed and the tank b is charged with water
of any temperature less than that at which the apparatus is required to be kept.
The lamp is then lighted and placed under the chimney, the weight r' is slidden
to the end of the rod 70 nearest the fulcrum of the lever and the screw
turned until the levers 7, ³, are supported by the rod 9 at such a height that the
damper shall rest on the chimney k. The water tray h is then filled with alightly
warm water and placed in the apparatus, and the egg drawer is put in its place
and the whole is allowed to remain until the temperature of the apparatus has
risen to about 103 degrees Fahrenheit. The eggs are then placed in the tray c¹ in
the drawer c and the said drawer is closed. If while the apparatus is in use it be
required to raise the temperature therein the weight is slidden along the rod pl
towards its free end a greater or less distance according to the increase of heat
required.
By my improvements the interior of the incubator is kept at a practically even
temperature, the increase of heat required to boil the liquid in the hermetically
sealed case or capsule n' and the decrease of heat required to condense the said
liquid being only a fraction of a degree.

page_text: That part of my Invention which consists in varying the position of a valve or
damper by mechanism connected with and actuated by the expansion and collapsion
of a hermetically sealed case or capsule containing a liquid which boils at the
temperature, at which the said mechanism is required to act is applicable to the
regulation of heat for purposes other than that to which I have described is as
applied.
Having thus described my Invention of "Improvements in Apparatus for
Hatching Eggs by Artificial Heat, which Improvements are in Part applicable to
other purposes," I wish it to be understood that I do not limit myself to the
precise details herein before described, as they may be varied without departing
from the nature of my Invention but I claim as my said Invention,―
First. The combination with such apparatus of a means for heating the water
contained therein, and of mechanism operated by the expansion and collapsion of a
hermetically scaled case or capsule containing a liquid which boils at the temperature
at which the interior of the apparatus is required to be kept, the said mechanism
being so arranged that heat shall pass to the water while the said case or capsule
is in a collapsed state, and shall be diverted from the water while the said case or
capsule is in an expanded state, substantially as hereinbefore described and
illustrated in the accompanying Drawings.
Secondly. The use in incubators provided with a supply of artificial heat of a
hermetically sealed expansible and collapsible case or capsule containing a liquid,
the expansion of the said case or capsule by the boiling of the liquid therein and
the collapsion of the said case or capsule when the liquid therein is at a temperature
lower than its boiling point governing the supply of heat to the said apparatus.
Thirdly. The use of a hermetically sealed expansible and collapsible case or
capsule containing a liquid as a motor for mechanism which is required to act at
certain temperatures, the liquid in the said case or capsule being such as will boil
or condense at the temperature at which the said mechanism is required to act.
In witness whereof, I, the said Charles Edward Hearson, have hereunto set
my hand and seal, this Twenty third day of May, in the year of our
Lord One thousand eight hundred and eighty two.