THE PRESERVATION OF THE FLUID, SUBSTANCE OF FRESH EGGS."
Year: 1855

page_text: LETTERS PATENT to Walter Christopher Thurgar, of Norwich, Surgeon,
for the Invention of "THE PRESERVATION OF THE FLUID, SUBSTANCE OF
FRESH EGGS."
PROVISIONAL SPECIFICATION left by the said Walter Christopher Thurgar
at the Office of the Commissioners of Patents, with his Petition, on the
18th July 1855.
I, WALTER CHRISTOPHER THURGAR, of Norwich, Surgeon, do hereby declare
the nature of the said Invention for "THE PRESERVATION OF THE FLUID SUBSTANCE
OF FRESH EGGS" to be as follows:-
It consists in the reduction of the whole fluid substance of fresh eggs to a
dry powder or flour, without coagulating the albumen of which it is composed,
thereby giving to it an extremely condensed and portable form, to be preserved
and used in any climate, suitable for all purposes to which the fresh egg is
applied, and especially convenient to the supply of ship's companies. And the
mode by which I effect this is this: I deprive the fluid substance of the egg
of its water by evaporation, by means of a stream of air and by the means of
heat moderated and conveyed through steam pipes placed under trays con-
taining the fluid substance of the egg; and after evaporation I reduce the
dried substance of the egg to flour by grinding the same in a mill worked by
a steam engine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Walter Christopher Thurgar in the Great Seal Patent Office
on the 12th January 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WALTER
CHRISTOPHER THURGAR, of Norwich, Surgeon, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of July, in the year of our Lord One
thousand eight hundred and fifty-five, in the nineteenth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Walter
Christopher Thurgar, Her special licence that I, the said Walter Christopher
Thurgar, my executors, administrators, and assigns, or such others as I, the
said Walter Christopher Thurgar, 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 "THE PRESERVATION OF THE FLUID SUBSTANCE OF FRESH EGGS," upon the
condition (amongst others) that I, the said Walter Christopher Thurgar, 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 per-
formed, 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 Walter Christopher Thurgar, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, that is to say:-
My said Invention consists of a mode of reducing the fluid substance
of fresh eggs to a dry powder or flour without coagulating the albumnen
which it contains, so that the material may be obtained and preserved
in a condensed and portable form, and be again dissolved or combined with
water when desired. for the purpose of being used, in like manner as fresh
eggs.
In order to reduce the fluid substance of eggs to a powder or flour, I first
deprive the fluid substance of its water by evaporation, which I prefer to effect
by means of currents of air passing over its surface when placed in convenient
vessels or apparatus for that purpose, so that the material may be dried' before

page_text: it has time to undergo any change from the action, of the atmosphere upon it
or otherwise, after which I reduce it to powder by grinding..
In the accompanying Drawings I have shewn Figures of an apparatus
convenient for drying the fluid part of eggs by effecting a rapid evaporation
of the moisture which it contains, at such a temperature as will avoid the
coagulation of the albumen which it contains, but any other convenient appa-
ratus may be adopted for that purpose.
Figure 1 of the said Drawings is a plan of the interior of the apparatus;
Figure 2 is a transverse vertical section of the same apparatus, taken through
the line W; X, Figure 1; and Figure 3 is a longitudinal vertical section of
the same apparatus, taken through the line Y, Z, Figure 1.
In these Figures, A, A, are trays, made of slate or any other suitable
material, with edges a, a, of the same or other fit substance, and raised to
about one inch in height above the faces of the trays. These trays are placed
on cases of wood about eighteen inches high, and the whole of the trays and
apparatus are enclosed in a chamber or case of wood or other material. The
trays may be warmed when necessary by the steam pipes b, b, b, b, but the heat
is to be so moderated as not to coagulate the albuminous substance of the egg.
At one extremity of the chamber or case, and about two inches above the tops
of the trays, there are narrow and horizontal openings c, c, c, of which the
length is equal to the breadth of the corresponding trays, as shewn in Figure 2,
and these openings communicate with the external atmosphere, so as to admit
the air. At the opposite end of the chamber or case are placed rotary fans or
air pumps d, d, d, as shewn in Figures 1 and 3. By these fans or pumps the
air contained in the chamber or case is drawn out, and thus a current of air
is caused to rush in at the same time by the openings at the opposite end of
the chamber or case, and a rapid and constant current of air is in this way
caused to pass over the trays in the direction shewn by the arrows.
Before pouring the fluid substance of the eggs upon the trays, the eggs
are deprived of their shells, and the yolks and whites are well beaten together
so as to break up completely the membranous structure of the egg, and
facilitate its desiccation. The material should be spread very thinly on the
surfaces of the trays at about the rate of the contents of three or four hen's
eggs to the square foot. When the egg has been well dried (the time for
effecting which will vary according to the state of the weather), it is reduced
to a powder or flour by means of a mill or other convenient apparatus. This
powder or flour should be packed in tin cases, bottles, or other convenient
vessels for preservation.
Having now particularly described the nature of my said Invention, and

page_text: the manner of performing the same, I declare that I do not intend to claim
the apparatus herein-before described, as being separately or apart from the
use or application of it in manner herein-before described, as any part of my
Invention; but that I claim as of my said Invention, the reducing of the fluid
substance of eggs to a dry powder or flour by desiccating and drying it at a
low temperature, and thus preserving the material in a fit state for future use
in manner herein-before described.
In witness whereof, I, the said Walter Christopher Thurgar, have
hereunto set my hand and seal, this Eleventh day of January, in the
year of our Lord One thousand eight hundred and fifty-six.
W. C. THURGAK. (L.S.)
Signed, sealed, and delivered in the presence of
GEO. JAY, Jun*.