IM-. PROVEMENTS IN APPARATUS FOR COOKING EGGS
Year: 1864

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of "IM-.
PROVEMENTS IN APPARATUS FOR COOKING EGGS."-A communication from
abroad by Edouard Prosper Malaport, of Paris, in the Empire of
France.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on
the 8th August 1864.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUS FOR COOKING EGGS," a communication to me
from abroad by Edouard Prosper Malaport, of Paris, in the Empire of France,
to be as follows:-
This Invention relates to a peculiar construction and arrangement of
apparatus for cooking eggs, whereby greater certainty and regularity in their
cooking are obtained. According to this Invention it is proposed to combine
with any convenient holder capable of containing one or more eggs. a
thermométer enclosed in a tube which is open on one side to show the
degrees or graduations. It will be found that three different graduations will
be sufficient, ranging from 163 to 167° Fahrenheit, inclusive, such being the

page_text: temperatures at which eggs are properly cooked. In using this apparatus it
is placed with the eggs in a vessel of water of the ordinary temperature,
which water is then to be heated in any convenient manner, and the
thermometer watched until the mercury has risen to one or other of the
graduations above referred to, according to the extent to which the eggs are
to be boiled, when the holder is to be removed from the water, and the eggs
will be found to be perfectly done.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on the
8th February 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of August, in the year of our Lord One
thousand eight hundred and sixty-four, in the Twenty-eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Henry Johnson, Her special license that I, the said John Henry
Johnson, my executors, administrators, and assigns, or such others as I, the
said John Henry Johnson, 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 APPARATUS FOR COOKING EGGs," a communication to me
from abroad by Edouard Prosper Malaport, of Paris, in the Empire of
France, upon the condition (amongst others) that I, the said John Henry
Johnson, my executors or administrators, by an instrument in writing under
my hand and seal, or under the hand and seal of one of them, should par-
ticularly 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 John Henry Johnson, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following

page_text: statement, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say:
•
The said Invention relates to a peculiar construction and arrangement of
ápparatus for cooking eggs, whereby greater certainty and regularity in their
cooking are obtained. According to this Invention it is proposed to combine
with any convenient holder capable of containing one or more eggs á
thermometer enclosed in a tube which is open on one side to show. the
degrees or graduations. It will be found that three different graduations will
be sufficient, ranging from one hundred and sixty-three degrees to one
hundred and sixty-seven degrees Fahrenheit, inclusive, such being the
temperatures at which eggs are properly cooked. In using this apparatus
it is placed with the eggs in a vessel of water of the ordinary temperature,
which water is then to be heated in any convenient manner, and the
thermometer watched until the mercury has risen to one or other of the
graduations above referred to, according to the extent to which the eggs are
to be boiled, when the holder is to be removed from the water, and the eggs
will be found to be perfectly cooked.
.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall
refer to the several Figures on the annexed Sheet. of Drawings, the same
letters of reference indicating corresponding parts in all the Figures..
Figure 1 represents the holder A, consisting of a plate perforated with a
number of holes, according to the number of eggs such holder is intended to
contain; B is a hollow tube fixed to the plate A, and enclosing the tube of a
thermometer, graduated as herein-before described, such graduations being
numbered 1, 2, and 3, or otherwise indicated. The liquid of the thermometer
may be either mercury, alcohol, or liquid colored or not.
In cooking eggs
the holder A with the eggs contained in the holes thereof is plunged into a
vessel C; containing sufficient water of the normal temperature to completely
cover the eggs. This vessel is then placed over a fire, or over the flame of a
lamp or gas jet, or is otherwise heated, and the temperature of the water is
thereby raised until the mercury of the thermometer rises to division
Number 1. At this temperature a portion of the albumen of the egg will
still be limpid, when the mercury rises to Number 2 division there will be
less limpidity in the albumen, and finally by the time the mercury reaches
Number 3 division the albumen of the eggs will be coagulated, and the eggs
should be removed from the water, as any excess of temperature will render
them hard. The division Number 2 indicates the point at which the eggs
will be soft inside, but it is never necessary to exceed the temperature

page_text: indicated by the division Number 3.. The system of boiling eggs by plunging
them into boiling water is defective inasmuch as an egg absorbs caloric
layer by layer, that is to say, that the portion of the albumen which is next to
the shell coagulates and hardens, and forms a covering a (shown at Figure 2),
which is a bad conductor of heat; the layer b which receives a less degree of
heat remains in a liquid or semi-fluid state. The heat thus acts consecutively
on the layers c, d, and e, and this action being impeded more or less by the
preceding layers, the interior of the egg will not be cooked uniformly.
By this improved system and apparatus for cooking eggs the heat will be
transmitted uniformly through the eggs. The apparatus may be modified in
various ways; for example, Figure 3 represents a wire gauze strainer A for
holding the eggs in lieu of a plate with holes in it, but still combined with the
thermometer; and Figure 4 is another form of holder, consisting of a vessel A
for holding the eggs, with straining holes in the bottom to allow the water to
run off.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that 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, the general combination and arrange-
ment of apparatus for cooking eggs, substantially as herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Eighth day of February, in
the year of our Lord One thousand eight hundred and sixty-five.
J HENRY JOHNSON. (L.S.)