Improvements in Microscopes.
Year: 1893

page_text: Date of Application, 11th Sept., 1893
Complete Specification Left, 11th June, 1891-Accepted, 28th July, 1894
Improvements in Microscopes.
We, WALTER CHARLES DAVIS, Fellow of the Chemical Society, and
WILLIAM DAVIS, Gentleman, both of The Manse, Prestonville, Brighton, in the
County of Sussex, do hereby declare the nature of this invention to be as
follows:-
Our invention relates to improvements in certain details in the construction of
compound microscopes.
In the ordinary form of stand used with microscopes of this class, the standards
on the tripod, to which the limb is jointed, are upright, but one of the features of
our invention consists in making the said standards sloping backwards, or leaning
towards the operator. This construction enables the joint on the limb to be set
further back than usual, the advantages gained being, that when the microscope_is
depressed to a horizontal position, the stage is thereby tilted further upwards,
which will be found a great convenience for such work as microphotography,
moreover the rack work of the stage is thereby brought more to the front and freer
from the joint, while the instrument is rendered more rigid, the centre of gravity
of the weight being well over the centre of the tripod.
A second feature of our invention consists in providing on the back of the limb,
at its upper end, a projecting part, having suitable recesses to form a convenient
grip for the finger and thumb, when it is desired to depress the instrument to the
horizontal, or raise it to the vertical, or other intermediate position.
The third feature of our invention consists in an improved construction of the
inner or sliding tube of the microscope, which is operated by the ordinary
rackwork.
As at present arranged it is impossible to apply lacquer to these tubes, for the
friction of sliding in the outer tube would at once rub it off, (moreover the lacquer
would interfere with the fit and smooth working of the tube) consequently they
rapidly tarnish and discolour by exposure to the atmosphere and become unsightly
in comparison with the other parts of the instrument.
According to our invention, we make the said inner tube of a couple of tubes,
fitting closely, the one within the other.
Along the whole part of the outer of the said tubes, which is exposed to view
when fully racked out, we cut away two long pieces, leaving only two narrow
strips of material parallel with the axis of the tube. The inner or lining tube is
then inserted and securely affixed by solder or other suitable means; the parts of
this tube exposed to view by the pieces cut out, as aforesaid, can then be lacquered,
and such lacquer, not coming in. contact with the inner surface of the main outer
tube, is not rubbed off, so that the sliding tube retains as bright and clean an
appearance as the rest of the instrument.
The strips aforesaid, which form the bearing surfaces, are necessarily not
lacquered, but they are practically unseen, one of them being placed in front and
concealed by the rack, which is affixed to it, while the other is placed behind or
underneath, and is preferably made a little broader than the front strip. The
bright lacquered parts or panels, are thus situated one on each side, where they
are most visible, greatly improving the appearance of the instrument.
The first and second features of our invention are found more particularly useful

page_text: when employing the higher powers, used for example in bacteriological investigations,.
but the said improvements are of value in all cases.
Dated this 11th day of September 1893.
AMBROSE MYALL,
2, Lancaster Place, London, W.C., Agent for the Applicants.
Improvements in Microscopes.
We, WALTER CHARLES DAVIS, Fellow of the Chemical Society, and
WILLIAM DAVIS, Gentleman, both of The Manse, Prestonville, Brighton, in the
County of Sussex, 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 :-
I
Our invention relates to improvements in certain details in the construction of
compound microscopes.
The parts of the instrument to which our improvements relate are the tripod
stand, the limb and the draw tube.
In the accompanying two sheets of drawings, which form part of this Specification,
and in which similar letters of reference denote similar parts throughout :
Fig. 1 is a perspective elevation of a compound microscope, constructed in
accordance with our invention.
Fig. 2 is an elevation of the draw tube extended.
Fig. 3 is a cross-section of the draw tube, to an enlarged scale.
Fig. 4 is a similar cross-section, shewing a slight modification.
Fig. 5 is a side elevation, to an enlarged scale, of the tripod and limb.
.
In the ordinary form of stand used with compound microscopes, the standards
on the tripod, to which the limb is jointed, are upright, or, in some cases leaning
forwards, or away from the operator, but one of the features of our invention
consists in making the said standards sloping backwards, or leaning towards the
operator.
Our arrangement is shewn clearly in Figs. 1 and 5, in which A. A are the
standards of the tripod, sloping backwards.
This construction enables the joint B on the limb C to be set further back on
the said limb than usual, leaving a greater space between the said joint and the
centre of the stage D, while the attachment of the stage to the limb is below the
joint. An advantage gained by this arrangement is, that when the microscope is
depressed to a horizontal position, as shewn by the dotted lines in Fig. 5, the stage
is tilted further upwards than would be the case in an instrument of the usual
pattern.
This is a great convenience in such work as photo-micrography, moreover by
this construction the rackwork of the stage is brought more to the front and freer
from the joint, while the instrument is rendered more rigid, the centre of gravity
of 'the weight being well over the centre of the tripod.
A second part of our invention consists in providing on the back of the limb C,
an' arrangement to form a convenient grip for the finger and thumb, when it is
desired to depress the instrument to the horizontal, or raise it to the vertical, or
any intermediate position.
This grip is constructed, as shewn, by providing a projection E on the limb,
thereby forming a curved place F for the reception of the finger and a projection H
forming a curved place J for the reception of the thumb.
The third feature of our invention consists in an improved construction of the
inner, sliding, or draw tube of the microscope, which is operated by the ordinary
rackwork.

page_text: As at present arranged it is impossible to apply lacquer to this tube, for the
friction of sliding in the outer tube would at once rub it off (moreover the lacquer
would interfere with the fit and smooth working of the tube) consequently it.
rapidly tarnishes and discolours by exposure to the atmosphere and becomes
unsightly in comparison with the other parts of the instrument.
According to our invention, we make the said draw tube of a couple of tubes L, M,.
see Figs. 2, 3 and 4, fitting closely the one within the other. Along the whole or
nearly the whole part of the outer tube L, which is exposed to view when fully
racked out, as in Fig. 2, we cut away long pieces, leaving only narrow strips N of
material parallel with the axis of the tube. The inner or lining tube M is then
inserted and securely affixed by solder, or other suitable means, the parts of the
tube M exposed to view by the pieces cut out of the tube L, form long panels,.
which can be lacquered, and such lacquer not coming into contact with the inner
surface of the main outer tube P is not rubbed off, so that the tube M retains as
bright and clean an appearance as the rest of the instrument.
The tube P is of larger size than usual, to accomodate the increased size of the
draw tube. The strips N, which form the bearing surfaces against the interior of
this tube, are necessarily not lacquered, but when there are only two of these strips,.
as shewn in Fig. 4, they are practically unseen, one of them being placed in front
and concealed by the rack Q, which is affixed to it, while the other is placed behind,.
or underneath, and is preferably made a little broader than the front strip. The
bright lacquered parts, or panels, are thus situated one on each side, where they
are most visible, greatly improving the appearance of the instrument.
We do not confine ourselves to the use of two panels and two strips; thus in.
Figs. 2 and 3, three panels and three strips are shewn, one of the said strips being.
placed in front and covered by the rack Q, as before described.
The first and second features of our invention are found particularly useful when
employing the higher powers, used for example in bacteriological investigations,.
but the said improvements are of value in all cases.
It is not essential that the stand employed with our improved microscope be of
the tripod form, as shewn, as any other suitable pattern may be used, provided that
the standards on it supporting the limb, lean back in the manner described.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what.
we claim is;
1. In a microscope, standards A, A, supporting the link C and leaning backwards,.
in the manner and for the purposes, substantially as herein set forth.
2. In a microscope, standards A, A, leaning backwards, in combination with a
limb C and stage D, in the manner and for the purposes, substantially as herein set.
forth.
3. In a microscope, the combination with the limb C, of projections E, H, and
curved places F, J, forming a finger and thumb grip, substantially as and for the
purpose herein set forth.
4. In a microscope, a draw tube consisting of an outer tube L, with portions
removed having bearing strips N and a lacquered tube M, fixed therein, shewing-
bright panels, substantially as and for the purpose herein set forth.
5. In a microscope, in combination, lean back standards A, A, a limb C with
projections E, H, and curved places F, J, and a draw tube having bearing strips N,.
with bright recessed panels between, all substantially as and for the purposes herein
set forth.
Dated this 11th day of June 1894.
AMBROSE MYALL,
2, Lancaster Place, London, W.C., Agent for the Applicants..