A NEW OR IMPROVED APPARATUS FOR TESTING EGGS
Year: 1868

page_text: LETTERS PATENT to Frederick Schäfer, of the Firm of P. and F.
Schäfer, of Golden Square, and of Piccadilly, both in the County
of Middlesex, Manufacturers, for the Invention of "A NEW OR
IMPROVED APPARATUS FOR TESTING EGGS."
Sealed the 9th April 1868, and dated the 11th February 1868.
PROVISIONAL SPECIFICATION left by the said Frederick Schäfer at
the Office of the Commissioners of Patents, with his Petition,
on the 11th February 1868.
I, FREDERICK SCHÄFER, of the Firm of P. and F. Schäfer, of Golden
Square, and of Piccadilly, both in the County of Middlesex, Manu-
facturers, do hereby declare the nature of the said Invention for "A
NEW OR IMPROVED APPARATUS FOR TESTING EGGS," to be as follows:-
The object of my apparatus is to test the freshness or quality of eggs.
The apparatus mainly consists of a reflector and of two apertures, the two
apertures being at right angles with each other, and each forming an
angle of 15 degrees with the reflector, so that the rays of light coming
upon the reflector from one aperture are reflected through the other
aperture.

page_text: In carrying out my Invention I fit in a box, of rectangular or other
form, a reflector inclined at an angle of 45°; in the top of the box I
form an aperture, and in one side of the box I form another aperture;
each of these apertures is provided with a tube preferably tapered
so as to concentrate the light upon the reflector. Then by placing
egg in the top tube the light passes through the egg to the
reflector and is reflected thereby through the side tube; by applying
the eye to this tube the quality of the egg can be seen; if the egg bc
good a clear yellow color is seen on the reflector, but if the egg be
bad the reflection will be spotted or dull.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Schäfer in the Great Seal Patent Office
on the 11th August 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
SCHÄFER, of the Firm of P. and. F. Schäfer, of Golden Square, and
Piccadilly, both in the County of Middlesex, Manufacturers, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of February, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Frederick Schäfer, Her special
licence that I, the said Frederick Schäfer, my executors, administrators,
and assigns, or such others as I, the said Frederick Schäfer, 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, "A NEW OR
IMPROVED APPARATUS FOR TESTING EGGS," upon the condition (amongst
others) that I, the said Frederick Schäfer, my executors or adminis-
trators, 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 performed, and cause the same to be filed in the Great Seal Patent

page_text: Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said Frederick Schafer, 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 thereof, reference being had to the
Drawings hereunto annexed, that is to say :-
The object of my apparatus is to test the freshness or quality of eggs.
The apparatus mainly consists of a reflector and of two apertures, the
two apertures being at right angles with each other and each forming
an angle of 45 degrees with the reflector, or the apertures and reflector
may be at any other convenient angle provided that the rays of light
coming upon the reflector from one aperture are reflected through the
other aperture.
In carrying out my Invention I fit in a box of rectangular or other
form a reflector inclined at an angle of 45 degrees; in the top
of the box I form an aperture, and in one side of the box I form
another aperture; cach of these apertures is provided with a tube
preferably tapered, then by placing an egg in the top tube the light
passes through the egg to the reflector and is reflected thereby
through the side tube; by applying the eye to this tube the quality of
the egg can be seen. If the egg be good a clear yellow color is seen
on the reflector, but if the egg be bad the reflection will be spotted or
dull.
:
The accompanying Drawings represent an egg tester constructed
according to my Invention in its most simple form.
Figure 1 is a perspective view, and Figure 2 a central vertical section.
A is a rectangular box; B is a reflector fitted in the box at an
angle of 45 degrees; C is a conical tube fitted in an aperture C¹ in the
top of the box; and D is another conical tube fitted in an aperture D'
in one side of the box. The egg to be tested is placed in the top of the
tube C, and the eye is applied to the tube D. To prevent any light
entering the box between the sides of the egg and the inside of the tube
Ca ring of caoutchouc or other yielding material may be fitted to the
top of this tube, as shown at E, Figure 3. Sometimes I fit a magnifying
made of any desired material,
glass in the tube D. The box A may be
may have
and
any
desired ornament applied to it, or it may be made of

page_text: any desired shape provided that the rays of light coming upon the
reflector B through the tube C are reflected through the tube D. I
sometimes fit a separate box F on the top of the egg tester, as
represented in Figure 4; this box may have a candle or lamp G
attached to it by a hinged joint at I; the inside of the box may be
silvered so that the reflected rays of light given off by the candle may
be concentrated by a deflecting plate K through the egg on to the
plate B. The box A may, if desired, be mounted on a stand or support
of any desired shape or design.
And having now described the nature of my said Invention, and
in what manner the same is to be performed, I declare that I claim, -
1. The reflector B combined with the apertures C' and D' in a box or
case in such manner that the rays of light coming upon the reflector
through the aperture C' are reflected through the aperture D', as herein
described.
2. The reflector B combined with the tubes C and D, as and for the
purpose herein described.
In witness whereof, I, the said Frederick Schäfer, have hereunto
set my hand and scal, this Tenth day of August, One thousand
eight hundred and sixty-eight.