Year: 1888

page_text: I, HENRY EDMUNDS of Rhodehurst St. Julian snoad
the nature of this invention to be as follows :-
This invention relates to the prevention of the loss by evaporation or otherwise of
the electrolyte in what is known as Secondary Batteries or Storage cells for Electrical
energy.
The object of my Invention is to obviate such loss as occurs generally in storage
cells by the dis-semination of spheroles of the electrolyte by the bubbling of the gases
generated in the cell.
In carrying out my invention I take the ordinary-well known forms of storage
cell-in which is placed the electrolyte and load or other plates, and pour onto the
surface of the electrolyte in a suitable fashion a liquid insulating substance--made
liquid by heat, so that the liquid insulator and electrolyte shall be in absolute contact.
According to the nature of the liquid-insulator I pour a greater or lesser depth onto
the electrolyte-so that it forms a solid compact cake or layer surrounding and
touching any projecting body above the surface of the electrolyte such as the lugs or
terminals of the cell.
At a suitable time I make a hole or holes in suitable positions in the insulator to
allow of the insertion of a hydrometer for testing the specific gravity of the electrolyte
and I may insert a peculiar ring-shaped device in glass or other suitable material so
fashioned that it will form, in conjunction with a cap a close joint and I may if I
desire put into the cap a tube of suitable material for the purpose of collecting and
conveying the gases of the cell, in a harınless manner, away from the storage battery,
and I may burn such gases by means of impinging them onto a piece of spongy
platinum, or otherwise.
In performing the foregoing operations I may use paraffin wax or such an insulating
material as will float on the surface of the electrolyte-or a combination of two or
more insulators and I may if desired raise the temperature of the electrolyte-during
or before the operation.

page_text: It will be seen that by this mode of covering the electrolyte nothing of a
foreign nature can get into the cell to cause either short-circuiting or mechanical
damage.
In charging a cell on which the foregoing operation has been performed, gas will
be evolved which will cause a pressure inside the cell and liquid will be forced out
which may be allowed to remain on the top of the insulator or I may syphon some of
the fluid out of the cell to prevent this.
It will readily be seen that plates may be used of some suitable-rigid material to
give additional strength to the layer of insulating material.

page_text: I, HENRY EDMUNDS, Engineer of Rhodehurst St. Julian's Road Streatham in the
County of Surrey do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This Invention relates to the prevention of the loss by evaporation or otherwise of
the electrolyte in what is known as secondary batteries or storage cells for electric
energy.
The object of my invention is to obviate such loss as occurs generally in Storage
cells by the dissemination of spherules of the electrolyte by the bubbling of the gases
generated in the cell, or by evaporation.
In carrying out my invention I take the ordinary well-known form of storage cell
in which is placed the electrolyte and lead or other plates and I pour onto the surface
of the electrolyte, in a suitable fashion, a liquid insulating substance rendered so by
heat so that the liquid insulator and electrolyte shall be in absolute contact.
According to the nature of the insulator I pour on a greater or lesser quantity so
that it forms a solid cake on cooling, surrounding and touching any projecting body
above the surface of the electrolyte, such for instance as the lugs or terminals of the
"couple."
At a suitable time I make a hole in a certain position in the insulator to allow of
the insertion of a hydrometer and I may affix a ring or other shaped device in glass or
similar material so fashioned that it will form, in conjunction with a cap, a closed joint
and I may fit into the cap a tube for the purpose of conveying the gases from the cell
in a harmless manner, away from the storage battery and I may burn such gas by
means of igniting it by spongy platinum or otherwise.
In performing the foregoing operations I use paraffin wax for ordinary purposes
but where the temperature varies, such as on ship-board or in hot countries I make a
compound of such materials as will not easily buckle-such as for instance, carnauba
wax, bee's wax, bitumen or their equivalents.
[ may also if desirable warm the electrolyte before or during the operation of pouring
on the insulator.
It will be seen by this mode of covering the electrolyte nothing of a foreign nature
can get into the cell to cause either short circuiting or mechanical damage.
In charging a cell in which the foregoing operation has been performed gas may
be evolved which will cause a pressure inside the cell and liquid will be expelled which
may remain on the top of the insulator and which will return, as a diminution of gas
or temperature takes place within the cell.
Where it is necessary I use a framework of some suitable substance to give strength
to the insulating cake. And I may form a ledge, projection or recess around the

page_text: inside of the cell to give support to the insulating cake and I siphon off a quantity of
the electrolyte so as to form a space or chamber between the electrolyte and the under
side of the insulating cake.
Having now particularly described and ascertained the nature of said
my
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The employment in Secondary batteries of a layer of insulating material poured
on to the Electrolyte which will set solid and form a protecting layer against injury to
the lead or other couples and may allow of a space between the electrolyte and under
surface of the insulator.
2. The employment of a covering of an insulating substance poured on to the
surface of the electrolyte or depolariser of an electric battery effected in the manner of
and for the purposes herein before described.
HENRY EDMUNDS.

page_text: Date of Application, 7th Apr., 1888
Complete Specification Left, 7th Feb., 1889
Complete Specification Accepted, 6th Apr., 1389
We Dr. HEINRICH LUDWIG HUGO SCHRÖDER of 5 The Terrace Clapham Common
in the County of Surrey Optician and JOHN STUART of The Hollies Clapham Common
aforesaid Optician do hereby declare the nature of this invention to be as follows :—
This Invention relates to a new and improved lens or lenses designed for use where
it is desirable to obtain plain images of large fields of view which shall be sharply
defined up to the margin as for example the case in photography.
According to my invention I combine two simple or uncorrected lenses of which
the outer lens is plano-convex and is composed of a glass of high refractive index
and low dispersive power the inner lens being plano-concave and being composed of a
glass of lower refractive index but of the same or preferably of higher dispersive
power.
The two lenses have their plane surfaces opposed to each other and are preferably
cemented together the two curved surfaces being portions of concentric spheres.
By proper choice of the radii of these spherical surfaces and of the glasses used and
of their thickness a corrected lens can be made to have a positive focus i.e. that is one
to give a real image of an object receivable on a screen and the corrections of
curvature and colour in such image may be made very perfect throughout a consider-
able angular distance from the axis. The ratio of the radii of the two concentric
spherical surfaces will depend upon the refractive indices and dispersive powers of
the glasses used.
The hereinbefore described arrangement may be slightly departed from either by
the two external surfaces not being precisely concentric or the two internal surfaces
precisely plane without departing from the substance of this invention but the best
results will be obtained in the manner above described.
Corrected lenses made as above described may of course be used also as
combinations.
" A
1 1000
J. H: JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C.,
Agents.

page_text: We, Dr. HEINRICH LUDWIG HUGO SCHRÖDER of 17 Althorp Road, Upper Tooting
in the County of Surrey Optician and JOHN STUART of The Hollies, Clapham in the
County of Surrey Gentleman do hereby declare the nature of this Invention and in
what manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
This Invention has for its object to provide a lens in which the errors of curvature
of the image and colour correction incident to other lenses are overcome and this
over a large field of view. Lenses made according to this Invention give a sharply
defined image throughout the field which is of great advantage in most or all
applications of lenses and especially so for photographic and other like purposes.
Hitherto all achromatic lenses (having either flat or other contact surfaces,
that give a positive image have the convex radius shorter than the concave radius.
Now the distinctive feature of the lens according to this Invention is that by
employing glasses combined as hereinafter described the radius of the convex surface
is enabled to be longer than that of the concave surface and at the same time a
positive image is still obtained. The convex and concave surfaces may thus be
arranged to represent parts of two concentric spheres.
According to this Invention the objective is composed of a convexo plano lens
made of glass of a high refractive power and relatively low dispersive power combined
with a plano concavo lens made of a glass of lower refractive power than that of the
glass of the convexo plano lens but of the same or higher dispersive power than that of
the glass of the said convexo-plano lens. The inner or contact surfaces of these two
lenses are placed together and preferably cemented the convexo plano lens forming
the front portion of the objective.
By proper choice of the radii of the spherical surfaces of the lenses and of the
glasses used and of their thicknesses an aplanatic lens can be made having a positive
focus that is a lens giving a real image of an object receivable on a screen and having
great flatness of field and suitable colour correction throughout a considerable angular
distance from the axis. The ratio of the radii of the two concentric spherical surfaces
will depend upon the refractive powers and dispersive powers of the glasses used as
hereinafter more fully explained.
And in order that our said Invention may be fully understood we 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 both the figures.
Figure 1 of the accompanying Drawings is a transverse section of an objective made
according to this Invention a being the convexo-plano lens of high refractive and low
dispersive power and 6 being the plano concavo. lens of lower refractive power and
the same or higher dispersive power. The convex and concave external surfaces
(marked respectively e and d) are portions of concentric or approximately concentric
spheres having their centre at 7 and the plane internal surfaces are preferably
cemented together at c.

page_text: In order to obtain a plane image throughout a large field of view the radii of the
external surfaces (e and d) should have a certain ratio to each other dependant on the
refractive and dispersive powers of the glasses used.
In practice it is found that the limits of the refractive powers of glass available for
the front lenses of the improved objective are from about 1.59 to 1.61 the index being
taken to be corresponding to the D line of the spectrum. Similarly the range of
refractive powers for the glasses available for the back lens of the said objective ranges
from about 1.50 to 1.53 the refractive index being as before that for the D line of the
spectrum. It is to be understood that these figures are. given as being what are
considered the best with glass as now generally obtainable.
With the before named glasses the ratio of the refractive and dispersive powers
which would produce the best radii so far as flatness of field and suitable colour
correction of the image are concerned is given by the following tables.

page_text: Thus for example if the front or convexo-plano lens a have a refractive power of 1.61
for the line I in the spectrum and the back or plano concavo lens have a refractive
power for the same line of 1.50 the ratio of the curves of the two spherical surfaces of
the lenses (e and d) should be 1-138 in order that throughout the field of view the
image may be plane with suitable colour correction.
Slight deviations may be made from the directions given above as for example by
slightly departing from the plane internal surfaces (c) or from the concentricity of the
external spherical surfaces (e and d) or from the ratio of the radii or dispersive and
refractive powers of the two glasses (a and b) given by the above tables without
departing from this Invention but we believe that by following the rules given above
the best results will be obtained with glass at present obtainable.
With the aid of these tables the requisite ratios of the dispersive power appertaining
to the refractive powers of the glasses used and also the requisite ratios of the radii
of the lenses may be calculated by the ordinary method of interpolation. The
objectives may be used singly as in Figure 1 or combined as in Figure 2 ( being the
diaphragm between them).
Having now particularly described and ascertained the nature of our said Inven-
tion and in what manner the same is to be performed we declare that what we
claim is.
1. The combination of a convexo plano lens made of glass of high refractive power
and relatively low dispersive power with a plano concavo lens made of glass of lower
refractive power and the same or higher dispersive power (the said lenses having plane
or slightly curved contact surfaces and outer concentric or approximately concentric
surfaces) to form an aplanatic lens or objective giving a positive image substantially
as hereinbefore described with reference to the accompanying drawings.
2. The improved lens or objective hereinbefore described.