IMPROVEMENTS IN OPTICAL INSTRUMENTS
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by the said Henry Edward Newton
at the Office of the Commissioners of Patents, with his Petition, on the
14th February 1866.
J, HENRY EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Mechanical Draughtsman, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN OPTICAL INSTRUMENTS,"
to be as follows:-
The improvements which form the subject of the present Invention are
principally applicable to different kinds of microscopes, and in general to all
optical instruments.
The improvements consist in the application to all optical instruments in

page_text: which it is required to cause one tube to slide on or in another of a screw
guide, whereby great precision and accuracy of motion for bringing the object
into the field is obtained. This screw guide consists of two or more toothed
or worm racks placed on each side of a central tube; the tube which encloses
them carries two grooves, in which the racks slide. The racks are actuated
by a screw or worm which encircles the instrument.
The next improvement consists in the use of an adjusting screw with differential
threads, and moving one in the other, and communicating a slow or rapid
motion to the stage of the microscope, or to the verniers of optical instruments.
The next improvement consists in the application of an universal joint to
microscopes and other optical instruments, which when adapted to the foot of
such instruments, and provided with a clamp, admits of the instrument being
placed in any desired position, and of being retained and fixed there by means
of the clamp.
The next improvement consists of a rotating micrometer composed of a plane
or curved glass, which is actuated by the moveable screw guides above men-
oned. Upon this micrometer glass are drawn graduated radial lines and a
spiral or convolute, the spirals or curved lines of which are equidistant. This
apparatus is applicable to microscopes, telescopes, or other analogous
instruments, in which it will serve as a goniometer.
The next improvement consists in the application of a moveable plate or
stage, which is supported by its centre upon the diaphragm or prism stage or
frame, which projects into the interior of the stage and allows the diaphragms
and prisms to turn and regulate the illumination of the object placed under
the microscope.
The next improvement consists in adapting to the fixed stage another stage
which is moveable on a centre with two plates connected together, so that the
object may be turned round.
The next improvement relates to a new kind of object glass and eye-piece;
these glasses are composed of two or three lenses, which may or may not be
parabolic, and are regulated by means of adjusting screws. The framing of
revolving lenses or glasses is made of a spherical form, and this may be applied
both to the eye-piece and the object glass, or to each separate lens or glass.
The instrument is so arranged and combined that the whole may be moved
together upon the foot or support by means of an adjusting screw or screws,
so that it may be raised or lowered as may be required.
The next improvement relates to binocular instruments, and consists in
making the tubes moveable on a hinge so that they may be adjusted to the
visual angle required. The angles of the prisms or reflectors which change

page_text: the direction of the image are also slightly increased. The frame of binocular
instruments is provided with an apparatus made in the form of a parallelogram.
which is moved by a screw. The tubes are connected together and move
symmetrically and simultaneously, so that they always preserve the same focus.
The apparatus may be provided with revolving lenses, so that the object glass
may be changed with facility. This parallelogram and revolving lens arrange-
ment may be adapted to other optical instruments. such as race or opera
glasses and telescopes, in which cases the luminous rays are directed towards
the eyes by moveable reflectors or prisms, the angles or edges of which are
made to cross slightly when the instrument has only one object glass. This
arrangement of binocular microscopes is applicable also to photographic
apparatus employed for producing simply photographic images having the
appearance of sculpture. A number of object glasses may be combined or
arranged together in juxtaposition, so as to see through them the same object
and project the images of it in one or more directions. by means of prisms or
reflectors. This arrangement is intended to admit of several persons seeing
the same object simultaneously. This may also be applied to photography for
obtaining the appearance of relief or intaglio. The eye-pieces and object
glass of binocular instruments may, if desired, be mounted excentrically so as
to admit of adjustment to suit the physiological conditions of the eye, as in
strabismus. A plano-concave lens is adapted to astronomical or terrestrial
telescopes for the purpose of shortening the length of the instrument while
preserving the same diameter or size of object glass and increasing the depth
of the focus. This same improvement may also be applied to the first or third
object lens of all microscopes to which the periscopic micrometer above
mentioned may be applied.
The next improvement relates to a binocular magnifying glass with a
varying width between the glasses, so as to admit of inclining the axes of
different groups of lenses, in order that notwithstanding the varying width the
object will always be found in the focus. The apparatus may also be pro-
vided with the revolving arrangement of lenses above mentioned, so that one
lens may be placed above another.
Another improvement consists in giving to the object stage a regular
travelling motion by means of small rollers connected by an endless cord.
The next improvement consists in the adaptation to microscopes and other
optical apparatus of a new kind of object glass, which is composed of three
lenses; the first is convergent, the second spheroidal or ellipsoidal, and the
third is of a periscopic form. The result of this arrangement is that the
luminous rays after having passed through the first converging lens enter the

page_text: second, which is spherical, ellipsoidal, hyperbolical, or parabolical, and cross
at its centre, and diverge until they reach its periphery, where they become
convergent and cross again before entering the third lens, which allows them
to diverge, which has the effect of correcting any spherical aberration, distortion,
and other defects of optical glasses. The prisms which cross the rays in
binocular and other instruments are of a double conical concave circular form,
and. they may be used in telescopes so as to dispense with the two glasses
between the object glass and eye-piece, the object of which glasses is to erect
the inverted image. The mirrors of the microscopes are metallic in place of
being made of glass. The parabolic, hyperbolic, achromatic, and other glasses
of optical instruments are composed of concentric layers united in groups.
The forms given to these glasses are obtained by a process which consists in
giving to the glass (when in a soft state) the form which is required, either by
centrifugal force or by means of a plate which will spread out successively the
layers of glass; or the object may be effected by placing one above the other
thicknesses of glass of different densities softened to the required point, and
then united together by means of heat.
The last improvement relates to an apparatus for producing these glasses
with concentric layers. It is composed of a central tube to which a variable
rotary motion is given, and which encloses channels for the supply of the air
and gas, whereby the fusion of the glass is effected. Upon this tube is placed
the mould or support of the lenses, which under the influence of the rotary
motion take their proper geometric form. The grinding and polishing of
these glasses in the form of an ellipse or parabola is effected upon a lathe for
turning spheres, and to which to the circular motion are added two transverse
motions, which admit of glasses of any of the above-mentioned forms being
ground and polished.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Edward Newton in the Great Seal Patent Office on
the 14th August, 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Mechanical Draughtsman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of February, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the

page_text: said Henry Edward Newton, Her special licence that I. the said Henry
Edward Newton, my executors, administrators. and assigns. or such others as
I, the said Henry Edward Newton, 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
"IMPROVEMENTS IN OPTICAL INSTRUMENTS," being a communication from Lcon
Jaubert, of the Boulevart Beaumarchais, Paris, in the Empire of France,
upon the condition (amongst others) that I, the said Henry Edward Newton
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
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 Henry Edward Newton, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say) :-
The improvements which form the subject of the present Invention are
principally applicable to different kinds of microscopes, and in general to all
optical instruments.
The improvements consist in the application to all optical instruments in
which it is required to cause one tube to slide on or in another of a screw
guide, whereby great precision and accuracy of motion for bringing the object
into the field is obtained. This screw guide consists of two or more toothed
or worm racks placed on each side of a central tube; the tube which encloses
them carries two grooves, in which the racks slide. The racks are actuated
by a screw or worm which encircles the instrument.
The next improvement consists in the use of an adjusting screw with
differential threads moving one in the other, and communicating a slow or rapid
motion to the stage of the microscope or to the verniers of optical instruments.
The next improvement consists in the application of an universal joint to
microscopes and other optical instruments, which when adapted to the foot of
such instruments, and provided with a clamp, admits of the instrument being
placed in any desired position, and of being retained and fixed there by means
of the clamp.

page_text: The next improvement consists of a rotating micrometer composed of a
plane or curved glass, which is actuated by the moveable screw guides above
mentioned. Upon this micrometer glass are drawn graduated radial lines and
a spiral or convolute, the spirals or curved lines of which are equidistant.
This apparatus is applicable to microscopes, telescopes, or other analogous
instruments, in which it will serve as a goniometer.
The next improvement consists in the application of a moveable plate or
stage, which is supported by its centre upon the diaphragm or prism stage or
frame, which projects into the interior of the stage, and allows the diaphragms
and prisms to turn and regulate the illumination of the object placed under
the microscope.
The next improvement consists in adapting to the fixed stage another stage
which is moveable on a centre with two plates connected together, so that
the object may be turned round.
The next improvement relates to a new kind of object glass and eye-piece;
these glasses are composed of two or three lenses, which may or may not be
parabolic, and are regulated by means of adjusting screws. The framing of
revolving lenses or glasses is made of a spherical form, and this may be
applied both to the eye-piece and the object glass, or to each separate
lens or glass. The instrument is so arranged and combined that the
whole may be moved together upon the foot or support by means of an
adjusting screw or screws, so that it may be raised or lowered as may be
required.
The next improvement relates to binocular instruments, and consists in
making the tubes moveable on a hinge, so that they may be adjusted to the
visual angle required. The angles of the prisms or reflectors which change
the direction of the image are also slightly increased. The frame of binocular
instruments is provided with an apparatus made in the form of a parallelogram,
which is moved by a screw. The tubes are connected together, and move
symmetrically and simultaneously, so that they always preserve the same focus.
The apparatus may be provided with revolving lenses, so that the object glass
may be changed with facility. This parallelogram and revolving lens arrange-
ment may be adapted to other optical instruments, such as race or opera
glasses and telescopes, in which cases the luminous rays are directed towards
the eyes by moveable reflectors or prisms, the angles or edges of which are
made to cross slightly when the instrument has only one object glass. This
arrangement of binocular microscopes is applicable also to photographic
apparatus employed for producing simply photographic images having the
appearance of sculpture. A number of object glasses may be combined or

page_text: arranged together in juxtaposition. so as to see through them the same object,
and project the images of it in one or more directions, by means of prisms or
reflectors. This arrangement is intended to admit of several persons seeing
the same object simultaneously. This may also be applied to photography for
obtaining the appearance of relief or intaglio. The eye-pieces and object glass
of binocular instruments may, if desired, be mounted excentrically, so as to
admit of adjustment to suit the physiological conditions of the eye, as in
strabismus. A plano-concave lens is adapted to astronomical or terrestrial
telescopes for the purpose of shortening the length of the instrument while
preserving the same diameter or size of object glass and increasing the depth
of the focus. This same improvement may also be applied to the first or third
object lens of all microscopes to which the periscopic micrometer above
mentioned may be applied.
The next improvement relates to a binocular magnifying glass with a
varying width between the glasses. so as to admit of inclining the axes of
different groups of lenses, in order that notwithstanding the varying width the
object will always be found in the focus. The apparatus may also be provided
with the revolving arrangement of lenses above mentioned, so that one lens
may be placed above another.
Another improvement consists in giving to the object stage a regular
travelling motion by means of small rollers connected by an endless cord.
The next improvement consists in the adaptation to microscopes and other
optical apparatus of a new kind of object glass, which is composed of three
lenses; the first is convergent, the second spheroidal or ellipsoidal, and the
third is of a periscopic form. The result of this arrangement is that the
luminous rays after having passed through the first converging lens enter the
second, which is spherical, ellipsoidal, hyperbolical, or parabolical, and "cross
at its centre and diverge until they reach its periphery, where they become
convergent, and cross again before entering the third lens, which allows them
to diverge, which has the effect of correcting any spherical aberration, distor-
tion, and other defects of optical glasses. The prisms which cross the rays in
binocular and other instruments are of a double conical concave circular form.
and they may be used in telescopes so as to dispense with the two glasses
between the object glass and eye-piece, the object of which glasses is to erect
the inverted image. The inirrors of the microscopes are metallic in place of
being made of glass. The parabolic, hyperbolic, achromatic, and other glasses
of optical instruments are composed of concentric layers united in groups.
The forms given to these glasses are obtained by a process which consists in
giving to the glass (when in a soft state) the form which is required, either by

page_text: centrifugal force or by means of a plate which will spread out successively the
layers of glass; or the object may be effected by placing one above the other
thicknesses of glass of different densities softened in the required point, and
then united together by means of heat.
The last improvement relates to an apparatus for producing these glasses
with concentric layers; it is composed of a central tube to which a variable
rotary motion is given, and which encloses channels for the supply of the air
and gas, whereby the fusion of the glass is effected. Upon this tube is placed
the mould or support of the lenses, which under the influence of the rotary
motion take their proper geometric form. The grinding and polishing of
these glasses in the form of an ellipse or parabola is effected upon a lathe for
turning spheres, and to which to the circular motion are added two transverse
motions, which admit of glasses of any of the above-mentioned forms being
ground and polished.
In Sheet 1. of the accompanying Drawings Fig. I represents in longitudinal
section the greater portion of the parts composing the improved microscope.
It is mounted upon an oval stand S by means of a single telescopic
Support K, K', or two pillars, as shewn at Fig. 2, which is a back view of the
forked piece C, Fig. 1; it is furnished with two axes A and A', so that it may
take any position, vertical, horizontal, reversed vertical for chemical purposes,
and oblique. It is held in any required position upon the axis A by the toothed
spring R, which, takes into the teeth of the collar D, and upon the axis A' by
the pin of the spring R' passing-into the holes in the collar (see Figures 1, 2,
and 4). The piece which forms the axis-A is placed at one of its extremities
in the toothed collar D, and at the other it forms the collar h, and terminates
in a socket round the tubular rod B, which supports all the other parts. The
arm B turns upon the head of the rod B, and carries the whole of the system
of optical instruments, comprising a compound monocular microscope; T, a
compound binocular one, and, lastly, a simple binocular magnifier Z, shewn
best at Figures 5 and 7. This arrangement allows each of the three apparatus
to be brought successively over the centre of the stage. The tubular rod B
has at its sides guide screws y, which serve by turning the screw nut E to
raise or lower the whole of the microscope, and to keep it in horizontal
positions; these guide screws are seen best at Figures 8, 9, and at Fig. 1,
Sheet I. These screw guides are formed by screwed tubes cut into the required
sections and fixed by means of screws and brazing. The tubular rod B has also
below the screw guides and extending to its lower extremity a groove, which
passes right through it, so that at the same time that it passes into the socket
of the stage; this latter fills it inside by the piece n (see Figures 1, 8, and 9,

page_text: and Fig. 1, Sheet II.) The rod B carries two adjusting screws V and V¹, the
thickest of which V is hollow, and screws into the part n of the stage.
and imparts a rapid movement to it: the other screw turns upon pivots at
its extremities, is tapped into the screw V, and by this means gives the slow
movement or fine adjustment. The helical springs r. r. are intended to make
up for lost time; n' (Fig. 9) is merely a loose nut. The tubes carrying the
object glass O and the eye-piece O' have also two movements. The quick
movement is imparted to them by the nut E. which is screwed upon the three
screw guides y fixed upon the sleeve M. (see Figures 1. 17. and 22). The slow
movement is given to them by the nut E screwed upon the screw guides y
of the tube T. In Fig. 22 the quick movement is produced by the female screw
E. and the slow motion by the female screw E. The section through . g. Fig.
23. shews the arrangement of the screw guides. The female screw E serves
to form the micrometer m in the eye-piece. (see Figures 1, 10, 11 and 22).
This micrometer is composed of a frame or mounting (the form of which
will be seen on referring to Fig. 11). The micrometer properly so called is
composed of a plane divergent or convergent glass according to the perfection
required for the optical part and the visibility of the divisions which it
carries. Fine radial lines r (Fig. 11) are marked upon this class, and also
a spiral lines consisting of equidistant coils and concentric circles in equal
numbers to the coils of the spiral and mixing with it on the radius r'. These
concentric circles instead of being entire may be simply marked by points or
lines at certain distances apart, and principally upon the lines. The last.
circle is entirely graduated. and above and at the sides are two moveable
verniers intended to facilitate the reading of the degrees upon the last
circle. The spiral may have its coils as close together and in as large number
as possible. and the divisions of the last circle as well as those of the vernier
may be by hundredths of seconds or by hundredths or thousandths of mille-
metres. Lastly, the micrometer may be accompanied by a moveable "reticula."
so that the measurement of the angles of crystals may be given instantly.
This micrometer is applicable to all kinds of optical instruments. such as
telescopes, polariscopes. goniometers, geodesical apparatus. &c.. The improved
object glass admits of perfect adjustment (that is to say). that the lenses
which compose it may be rendered independent of one another and brought
closer to or further from each other. The screw nut E brings the second
lens nearer the first or third, the screw nut T moves the third lens nearer to
or further from the second. The outer tube which carries the rings b, b'. and
the first lens is screwed to the rest of the apparatus: this outer tube with
its rings is shown detached at Fig. 12, Fig. 13 represents an object glass,

page_text: In-
Two
the second lens of which is fixed. and the two others moveable independently
of the second. The preceding Figures accompanied by the two sections,
Figures 14 and 15. shew the arrangement of these screw guides. The screws
E and E may be set in both arrangements at such a distance from each
other that they may be worked either together or separately. Besides the
springs with square coils there are others upon each ring and in .cach
female screw, for the purpose of relieving the movement from stiffness.
dexes, not shewn in the Drawing, are placed above the female screws.
openings s. s, made in the outer tube allow of the entrance of the light
condensed by prisms, mirrors, or reflectors upon an opaque object even
with the employment of the greatest magnifying power. even with glasses
where the system of immersion is employed. Each of these openings is
furnished with a small thin tube of silver or copper in order to prevent the
dust from entering between the first and second lenses. This light may be
polarized by means of a prism made of Iceland spar or any other polarizer,
and colored or monochromatized by a lens or plate of rock crystal. The eye-
piece O' is also adjustable: it will be hereafter described, as well as the optic,
dioptric and catoptric parts of the microscope. The object and eye-glasses
are mounted ipon revolving holders with spherical bases R and R', as
shewn at Fig. 17, and deiached at Figures 18, 19, and 20. and Figures 1
and 20. Sheet II. The revolving holders may be connected together by a
rod, see Fig. 31. Sheet .. so that the eye-pieces and object glasses may be
changed simultaneously. Figures 5 and 7. Sheet. 1., shew an elevation and
sectional plan view of a portion of Fig. 1. The tubular part
two binocular tubes seen in Fig. 7 and in Fig. 4. Sheet III.
the movements for adjusting the tubes at the proper distance to suit the eyes
of the person using the instrument by means of the screw E; the pinions i, i,
serve to focus the inner tubes. The other details of this arrangement are
shewn in Sheet III. M is the sleeve of the tubes of Fig. 1. and Z is a rod
carrying the binocular lens 1. The screw E serves to move the lens back-
ward or forwards more or less over the object. The hinges c. c, and the two
joints c², c. serve to put the lens into such a position that, whatever may be the
length of focus, the optical axes may always be placed at the required distance
from the eyes of the observer by means of the screw V. The hollow rods e
are also anoveable upon their axes. The lenses may be slotted at their lower
extremities when the focus is short and the tubes are very much inclined.
Fig. 21 is a sectional view taken through the line U, V, Fig. 5.
return to the socket of the stage 7. Figures 1, 3. 27. and 8.
left hand the groove (Fig. 3), in which slides the jointed support of the
is one of the
Fig. 7 shews
We will now
It has at its

page_text: mirror, and on the right the lugs for the reception of the rods of the diaphragm
carrier, the prisms d', achromatic condensers, &c. (see Figures 1, 3, 8, 16, 27,
and 29). The part of the mirror carrier (Figures 1, 16, and 8) is
cylindrical and capable of turning in its socket, so that it may be made to
assume any desired position by means of its joints. Figures 24, 25, 27, 28,
and 29 shew the arrangement of the diaphragm carrier d, the mode of centering,
regulating, and guiding, shewn also in Figures 3, 7, 8, and 10, Sheet II. The
diaphragm carrier. has a socket, in which passes a steel rod fixed at its upper
part in the stage and at its lower part upon a lug on the socket of the stage.
By turning the screw ES the diaphragm carrier is caused to descend, and when
it has arrived nearly at the end of its course it comes from under the stage,
when it may be brought back and set at the required height by turning the
screw in the reverse direction. The diaphragms d', as shewn at Figures 27 and
28, are mounted upon excentrics, and are made to extend when required to the
edge of the upper face of the stage. The diaphragm or its excentric is turned
by means of a plate p capable of moving in a circular direction and projecting
slightly beyond the lower edges of the stage, as seen at p. Figures 24 and 27.
Fig. 25 shews two plates p', p', an upper and a lower one, with their mode of
junction; they form a frame moveable in a circular direction.
The upper
plate is generally covered with a black glass and graduated for the purpose
of measuring the angles in the application of the apparatus to polarization and
crystallization. Upon this plate is the point of attachment of the holder q.
This holder is jointed and has solid arms, as seen in Figures 25 and 26.
It is suflicient to put the finger upon in order that the preparation may
become entirely free. It has also two small arms e, e, provided with coiled
springs which retain the extremities of the object carrier.
In Sheet II., Fig. 1 represents the same microscope as that shewn in
Fig. 1, Sheet .. in which the arm B is of one piece with the hollow rod B;
its position is such as would be given to it for certain chemical studies. At d
is a prism or reflector. which reflects the image of the object in the direction
of the ocular tube T. The picce q is a cover, and the screw Ve is intended
to raise or lower the reflecting prism. This prism may separate the rays of
light into two parts in order that they may be received by one of the binocular
systems, which will be alluded to hereafter. Fig. 2 shews in plan view a piece
intended to connect the eye-piece tube with the tubes of the object glass O.
When the apparatus is intended to serve for taking photographic pictures it
is placed upon a camera obscura N invented for that purpose. The cover 4
is withdrawn, and the prism d is placed upon a small slide or drawer with
adjusting screws, not shewn in the Drawing, and the object is brought to the

page_text: required position by looking through the eye-piece carried by the tube T¹.
The prism d is withdrawn instantly into the tube T' by means of its slide, and
the image of the object is thrown upon the rough glass or the sensitized paper
placed at y. The required position may also be obtained by looking at the
image of the object through the tubular binocular openings m made at the
side of the camera, and one of the opening tubes of which is shewn at the side.
It is not more difficult to photograph the object when the apparatus is placed
horizontally. The camera is placed upon its feet P, P, and the desired
focus is obtained either with the eye-piece tube and prism or by looking
directly at the image upon the unpolished glass; the arrangement of the
improved camera renders the thing as easy for the unreversed vertical position
as for the two other positions, viz., reverse vertical and horizontal. The
camera is to be placed upon the instrument instead of being underneath, and
rests upon the forked piece C and upon a sliding stop rod situate at H in the
camera. The required focus is obtained by means of the ocular tube placed
horizontally at the side and with an arrangement analogous to that of Fig. 1.
This camera may also serve for the reproduction of objects by means of
photography either with each of the three apparatus shewn at Figures 1, 5,
and 7, Sheet I., or with those shewn at Figures 3, 7, 11, and 20, Sheet II.,
and also with all the arrangements of apparatus shewn in Sheet III. at
Figures 1, 4, 6, 10, 14, 17, 18, 21, 22, and 23), and this in all possible
positions, with one, two, or more images either set over one another or
separate. The microscope represented at Figures 3, 4, 5, and 6 is identical
with that of Fig. 1, except that the axis of rotation is in the arm B' instead
of being in the toothed collar fixed in the forked piece C, Fig. 3, and the
sections 4, 5, 6, shew sufliciently the details of construction. The microscope
shewn at Figures 7, 8, 9, and 10, Sheet II., as the same movements as the
preceding, the same mode of illumination, and the same diaphragm carriers,
but its stage has no vertical movement. The piece A' forms part of the stage
and serves as a support for the axis of rotation and collar of the mirror.
The
stage is moveable in a circular direction in the same way as the stage known
as Strauss's. The microscope may be mounted upon telescopic supports in
the same way as those previously described. The piece which in Fig. 1.
Sheet 1, forms a socket round the rod B forms also a socket for the tubular
parts J, J, and at the same time constitutes the stage. The quick movement
is given by the female screw E, and the slow movement by the female screw E.
Other movements may be given to the tubes as well when they are mounted,
as those in Fig. 1. as when like those in Fig. 22. Sheet 1. As this microscope
is intended specially for dissection it is furnished with a binocular lens similar

page_text: to that shewn in Figures 5, 7, Sheet I., or Figures 26 and 27, Sheet III.;
Fig. 13, Sheet II., is a section taken through K, K, Fig. 7, and shews the
form of the upper extremity of the tube t. The pad E of the arm B' is
capable of turning upon the head t', and allows of the binocular lens being
brought above the centre of the stage. The female screw E serves to
advance or bring back the rod Z to a greater or less distance from the lens.
Concentric adjusting screws arranged in a different manner from that shewn
at Fig. 1, Sheet L., are also employed in order to raise the tubes t, t.
Fig. 14 shews an arrangement by which the screw guides of the improved
object glasses are applied to the adjustment of single, double, or triple glasses;
Fig. 1 is a plan view of the same; Figures 16 and 17 represent the improved
system of adjustment as applied to compound eye glasses of any description;
and Figures 16, 18, and 19 represent the improved mode of centering the
eye-pieces with respect to the object glass by means of excentrics or a system
of screws such as that shewn at Figures 4, 27, and 29, Sheet III. The
system of adjustment (correction) is applicable to all optical instruments, and
the centring is specially applicable to binocular apparatus. Fig. 20 represents
the improved microscope converted into a solar microscope.
The stage
is attached by screws to the table G; on turning the head of the central.screws
V, V, of the rod B, the object glass will be moved nearer to or further from
the stage.
The optical part of the microscope is shewn in Fig. 21, Sheet II.,
and the following Figures. It is composed of lenses or series of lenses, the
arrangement, form, and composition of which are special. The first lens is
plano-convex; the second, which may be composed of two parts, is a complete
ellipsoid or formed of two parts of ellipsoid, or hyperboloid, or paraboloid, or
even simply a spheroid. In certain cases it may be divided into two parts
(see Fig. 22) plane or cut out at their centre, with such a curve (see Fig. 23)
that the rays which come from the object's shall arrive at the face d, leave it,
and after crossing each other shall penetrate the face b, and emerge
from the face c after a fresh refraction, which shall render them sensibly
parallel. They are rendered divergent by the periscopic lens M, Fig. 21.
If this lens is replaced by another which is plano-convex or a divergent
periscopic meniscus (Figures 24 and 25), the rays will cross each other
again at , and the image will be again turned round. The lens d, d',
instead of having its centre cut out may have it formed of a lump
thicker than the rest; it may also be cut or shaped as seen at Figures
26 and 27. The lenses may be neither complete ellipsoids nor hyperboloids,
and may be set at variable distances (see Figures 23, 26, and 27).
lenses L, L, are shewn on a scale larger than the real size. This arrange
The

page_text: ment of object glass is applied in all its variations to all optical apparatus to
which it may be applicable, especially to photographic apparatus, as well to
simple as to compound ones, which will be hereafter alluded to. The improved
eye-piece is composed of a convergent periscopic or non-periscopic meniscus,
placed as shewn at Fig. 21, and of an ordinary eye-piece. Fig. 28 represents
an eye-piece in which the divergent periscopic or non-periscopic glass is placed
near the eye-piece. All the improved lenses are composed of glass in simple
concentric layers, or in groups laid one upon the other and rendered adherent,
or fastened together, and arranged under conditions of thickness, arrange-
ment, curvature, dimensions, and powers of refraction and dispersion even
variable from the centre to the edge, such that not only are they completely
achromatic, but moreover, whatever may be their form, even spherical, they
may be completely deprived of spherical aberration, chromatic aberration,
astigmatism," and distortion, and give the chemical focus at the same mathe-
matical point as the optical focus. These layers, either colored or not, are
applied to the glasses of all optical instruments, spectacles, eye-glasses, field
glasses, and telescopes, and not only will these superposed layers of analogous
form and arrangement serve in certain cases like that of the animal crys-
talline lens, and in other cases simply superposed serving for the production
of complete achromatism, but also under certain circumstances arranged in a
manner contrary to the preceding arrangements they will serve to produce the
maximum of chromatism and the separation of the chemical focus or optical
focus or even of the entire or partial spectrum or the neutral tints, &c. &c.
for the production of the effects of polarisation and interference.
I will
hereafter describe the processes by means of which the lenses represented in
the apparatus shewn.in Sheets I., II., III., IV., and V of the Drawings, or
of any other forms or dimensions, may be produced. Fig. 29 represents a
double convex lens formed of concentric layers, the chemical and optic foci of
which meet at the same point without aberration of any kind. Fig. 29 bi is
a double concave of the same arrangement. Fig. 30 represents an object
glass composed of a series of three lenses achromatized by concentric layers
superposed, and in the form of an ellipsoid, hyperboloid, or paraboloid, or
simply a spheroid. Figures 31, 32, 33 represent prisms formed and achro-
matized by a system of concentric layers having a maximum of dispersion for
all the rays of the spectrum, or only for certain of them, according to the
nature and arrangement of the layers. Figures 34, 35, and 36 represent one
of the reversing prisms, which magnifies by reflection and by refraction; if
the face c is concave it may even constitute a single Galilean glass. Figures
37 and 38 represent, another form of reversing and magnifying prism. From

page_text: the face d the rays are reflected upon the silvered face b. which is convex.
spherical, or parabolic. and are reflected on to c. where they form a focus.
Figures 39 and 40 represent in its mounting a conico-concave prism with
reflected rays convergent or divergent, and the effect of which combined with
an eye-piece is singular. Figures 41 and 42 represent a similar prism, but
having parallel rays, and intended like the preceding for throwing light upon
microscopic objects, and for photographic apparatus for producing black or
dark parts, framing, &c. They may be round, oval. or of any other suitable
shape. Figures 43 and 44 represent another prism of a conico-concave circular
form, intended to produce a magnifying effect by reflection upon its faces, and
for reversing any luminous ray. Figures 45, 46, 47, and 48 represent the optic
catoptric portion of a microscope, together with its optic dioptric part: it may he
employed as well with one as with the other. This optic part is formed first of a
lens or mirror for condensing the light of a meniscus diverging lens M, which
lengthens the bundle of luminous rays of a silvered parabolic reflector y of an
object carrier, Figures 45 and 46. and of an eye-piece O. In Figures 47
and 18 the object is supposed to be transparent and placed at x or s¹; y¹,
and y" are silvered reflectors, the one convex and the other concave.
In Sheet III., Fig. 1 represents a binocular microscope, with a mode of
producing a variable separation of the tubes, and having a single object glass;
adjustment of the focus is effected by means of the screw collars E, E. The
tubes t, t, are after crossing again united at their lower extremities by two
hinges c. seen at Fig. 2, and may be separated at their upper extremity by
The two prismis p
means of the reversely threaded screw, Figures 1 and 3.
which divide the rays coming from the object glass follow the motion of the
tubes upon their hinges. One of the two prisms is placed a little higher than
the other, in order that the rays may not pass between their angles, which
may in this manner cross each other more or less. Figures 4 and 5, Sheet III.,
represent a front view of the binocular microscope. which has already been
seen in part at Figures 5 and 7, Sheet I. The variable separation of the
tubes, as well as their drawing motion, take place, as has been seen at
Fig. 1. by means of the milled heads E, and by the pinions taking into
racks fixed upon each of the interior tubes. The hinges c. c. are seen in
Fig. 5; the Drawing is sufficient to shew the working of all the
compose the whole of this form of microscope.
conical, circular, concave, and truncated, reverses the image by causing the
rays to pass to the left which it has received from the right, and those to pass
to the right which it has received from the left. Figures 6, 7, and 8, Sheet III.,
shew other arrangements of prisms or reflectors either plane or curved, the
parts which
The prism p', which is

page_text: object of which is to divide into two parts. the rays coming from an object
glass of any kind. and to render them binocular: this arrangement allows of
the visual angle being preserved and the angle of the two eye tubes being
equalized. Although two of the prisms or reflectors are not placed in the
same plane, they have nevertheless no influence upon the extent of the
luminous rays and the dimension of the rays which pass through them. A
reverse threaded screw allows of the prisms p. pl. being separated. and another
similar screw serves also in move the prisms p. p. into the positions shewn at
Fig. 9. and which then furnish images of another kind: these screws are not
shewn in the Drawing. With reflectors formed by a sector of a cylinder
(Fig. 8) images different from the preceding are obtained, and present singular
effects. which with their applications form part of this Invention. Figures
10 and 11 represent a binocular microscope with double objeci glasses. It
may be mounted instead of the binocular instrument f. f. Figures 5 and 7.
Sheet I., or placed upon the hollow rod B. or upon that shewn at Figures
1. 3. or 11. Sheet II. The glasses are brought to the required focus by the
screws of the tubular red B. and also by the slow movement by means
of the screw collar E. The two tubes are made to suit the variable
distance of the eyes of the observer by turning the head of the long
screw which acts by means of two different proportioned screw threads
upon the arms b. b. b. b. so that the tubes t. 1. can be made to recede
from each other until the arms b. b. are parallel in two planes passing
through their points of attachment. without the object leaving the focus.
Each tube is furnished with revolving object glass holders having three
or four object glasses: this might also be the case with the eye-pieces.
Fig. 12. Sheet III.. represents one of these revolving
the object glasses being removed. The tubes of the object glasses are cut
away when their focus is very short: g. g. and q. q. are guides. Fig. 13
shews the manner in which the tubes may he connected with the hollow rod B.
or to any other stand. Fig. 14 represents a portion of a microscope which
may be binocular, in order that two persons may inspect the same object at
the same time. The lenses 1. 11. 1. arc slightly cut away. as shewn in Fig. 16.
The function of the prisms or reflectors is clearly indicated in the Drawing.
objeci glass holders.
Fig. 1 shews another modification of the binocular microscope, and is
intended to give views of the same object at different angles. so that the relief
of the object is considerably augmented. Figures 18 and 19 shew the mode
of uniting a large number of object glasses. each of which gives a somewhat
different view of the object. Figures 20, 21. 22. 23, 24, 25, show how all
these various views may be brought to bear upon the same eye-piece or upon

page_text: the same point, or upon different points. These object glasses may be made
all to magnify to the same or to different extents. It will be understood that
cach of the multiple object glasses which are here represented by simple or
achromatic lenses may be composed of several lenses superposed and periscopic,
or not, and that they may vary in form and be moveable individually in their
mountings. These binocular microscopes having one or more object glasses,
or having several object glasses and one eye-piece, are also intended for
photographing objects. and for reproducing them with forms and reliefs
resulting from these arrangements. These views may be superposed com-
pletely or partially. and be of equal or different dimensions, or different views
of the same object. but of such dimensions that those which reproduce the
same plans shall be larger or of greater magnifying power. and the others
smaller, or vice versa. They may be combined in such a manner as to repro-
duce with incomparable perspective and fidelity the object, scene, or landscape
photographed or under view, and, so that plane images drawn upon paper
shall appear to be in relief as if looked at through a stereoscope. The various
apparatus may be made of any dimensions. If these object glasses are
reversed. and the object to be reproduced be then far off, and the image
reproduced near, all these arrangements will be applicable to ordinary pho-
tography. In order that the images produced may have a life-like appearance
or be well brought out, the object is illuminated and shewn projected into
shade by the employment of the illuminating prisms. This principle is also
applied to ordinary photography, in which case the person or object to be
photographed is to be placed in the greatest obscurity, in fact, as in a camera
obscura, and is then illuminated by means of a very small opening, the light
being only suffered to fall upon and to be reflected by the object, any extra-
Upon
neous rays of light being absorbed by black velvet or other fabric.
objects of comparatively small dimensions light is projected, which is rendered
sensibly monocromatic by a prism of Iceland spar or other suitable substance,
and a plate of rock crystal of variable tint as before mentioned. Figures 26
and 27 represent in side view and plan a binocular glass intended for the use
of engravers. for dissections, etc., in which the lenses may be adjusted at
The axis of
varying distances at the same time that the focus is preserved.
the hinge c must correspond with the focus of the two lenses in order that the
object may not leave the focus on increasing the distance between the tubes
Figures 28
by the female screw working on the double-threaded screws V.
and 29 shew plan and side views of a hand glass of similar construction, the
The lenses of each of these
arms of which may or may not be crossed.
mountings may be adjustable, or may be only a single achromatic lens, or an

page_text: arrangement of periscopic or other lenses. Fig. 30 represents a double opera
or field glass, the tubes 1, 1, of which instead of remaining parallel may be
always brought into the direction suitable for the angle of vision. It is
sufficient for this purpose to turn the excentrics R. R, in order that the tubes
may be slightly inclined upon the pins d. They cannot be inclined in the
other direction out of parallelism as they are held in position by the contact
guides s. Fig. 31 shews the play of the excentric, Figures 32, 33, 34, shew
the details of construction. The eye-pieces may also be excentric with respect
to the object, even in cases where they admit of several changes. This
arrangement (as will be seen on reference to Figures 30 and 36) is the same
as that mentioned with reference to Figures 18 and 19. Sheet II.; the focussing
is effected upon two screw guides by means of the button B.
represents a double opera or field glass. the tubes of which may be set at
varying distances apart to suit different eyes: the eye-pieces draw out and
may be set excentrically as in the former instance. The drawing or sliding
Fig. 37
of the eye-pieces for the purpose of focussing is effected by means of the
button B, and the separating movement of the tubes by the button c, q, and
its accessories, the right and left handed threads of the stem of which take
into the female screws E, E'. carrying the links b, b', attached at their other
extremities to the tubes f. f. A. A', are the supports and guides. If the
part q only of the button be acted upon the tubes are brought into the visual
angle by acting upon c. they are brought into a parallel position by acting
upon c, q, both at once; the parallelism and angle remain as they were, but the
tubes are brought nearer to or further from each other. Figures 40 and 41
represent the optical part of an apparatus, a compound object glass, similar
in principle to that shewn in Figures, 14 and 16, and is intended for obtaining
various views over a large field. Figures 42 and 43 represent an analogous
arrangement, but with magnifying prisms p for the purpose of obtaining a
still more extended field, as magnifying prisms of single or even double reflection
bring to the eye the images of objects placed before the person and also of
those placed a little in the background. If especially the prisms p project to
a short distance beyond the tube the person will be able to see all round and
even behind himself. The lenses of object glasses as well as eye-pieces may
be periscopic, and either consist of a single lens or of several layers of glass,
and the magnifying power and number of lenses may be greater or less, and
they may be mounted in double frames or in any other manner.
In Sheet IV., Figures 1 and 2 represent an arrangement of simple photo-
graphic lens. The lens in this case is formed of superposed layers, and is
suitable for taking in a large field; it is free from spherical and chromatic

page_text: .
held by a dovetail upon the ring B,
aberration and astigmatism, and it has a flat surface; it embraces a consider.
able angle, and has very little need of a diaphragm. The lens L is focussed by
means of the screw guides r. To this apparatus is adapted the system of
diaphragm shewn at Figures 24. 27, and 28; Fig. 2 represents a compound
photographic object glass. The apparatus represented at Fig. 3 is a mega-
scope or projection apparatus. The improvements relating to it consist, first,
in the employment of lenses formed of concentric layers; second, in the
employment of the object holder h for holding the object (Figures 5, 6, and 7);
third, in a longitudinal movement of the lenses for adjustment to the focus by
means of screw guides; fourth, in a rotary motion given to the object to be
projected by means of the ring B; fifth. in a reciprocating motion of the
object carrier by, the four rollers q, two of which are connected together by
means of an endless chain c, and are worked by the crank handle M. Two
endless screws mounted upon the same shaft and taking into two pinions fixed
upon the axles d, d, might give the same movement as the chain or band c.
The four rollers, which all rotate, are covered with caoutchouc in order the
better to carry with them the object plate. Figures 5, 6, and 7 shew in plan,
side, and end views the object holder
the object being placed under the arms The lens L, formed of superposed
layers and of any suitable form, may be placed at L' behind the object to be
projected. This apparatus constructed of larger dimensions may also serve as
an apparatus for enlarging photographs. Figures 9 and 10. Sheet IV.,
represent an arrangement of prisms with screw guides as applied to constitute
a binocular ophthalmoscope, and for varying the distances of separation of the
luminous rays. The two prisms p' are moveable with respect to the two
others p by the female screw e. The two prisms p might be moveable also,
either upon a hinge, as in Fig. 1, Sheet III., or those in Fig. G. Figures 11
to 16 represent various views of a binocular telescope. It has two bodies, and
the object glasses are cut away to allow of their being brought into close
approximation with each other. The inverting glasses S are, as well as the
eye-pieces, mounted upon revolving holders. The two bodies K, K', may be
set at varying distances to suit the eyes of the observer. The separation of the
tubes K, K', is effected by means of the long screw V working in the female
screws E. The four links b, which form a parallelogram, are attached at one
of their extremities to the female screws E', and at the other extremities they
are fixed upon the slides sliding in the collars G fixed upon the bracket Q.
as seen in Figures 11, 12, and 13. The two slides of each of the tubes might
be connected together by two slight rods extending from one to the other at
the sides of the tubes K, K. This arrangement allows not only of the adjust-

page_text: ment of the distance apart of the tubes, but also of giving to the tubes either
perfect parallelism or a slight angle conformable to the visual angle, a little
larger opening being given to the links at the end next the eye-pieces by
means of a female screw e¹, Fig. 16. This female screw carries a stop bolt
(seen at Figures 5, 10, and 11) in the following Sheet. Two other links
might also be placed at D. Figures 12 and 13 shew also the place for the
finder C. The required focus is obtained in two or even in three ways.
first, by the ordinary drawing in or out of the tubes J; second, by sliding the
tubes by means of an arrangement of racks and pinions, such as that shewn
in Figures and 9 of the following Sheet, or by two endless screws taking
into the two female screws E toothed for that purpose and acting upon screw
guides which are placed upon the tubes J'; thirdly, and lastly, by means of
the female screws E acting upon the screw guides of the tube T carrying the
piece N upon which the revolving holders R and R' are mounted. This
telescope may be used as a celestial telescope either by pushing in the tubes
J, J, bringing the tube S', which has no glass, into the place of S, and
changing the eye-pieces, or by substituting shorter eye-pieces; these eye-
pieces, terrestrial as well as celestial, may be adjustable as before mentioned.
Fig. 14 is a section taken in the line C, D, of Fig. 11, and Fig. 15 is a section
taken in the line I, J, the tubes being removed, and it shews the form of the
piece N and also that of the revolving holders R. The screws V allow of the
revolving holders R. R', being removed with facility. fare ribs or feathers.
The telescope is moveable on the piece Q which carries a large moveable
circle upon another which belongs to the foot, and the zero of which must
always be in the plane of the meridian. Figures 21, 22, and 23 represent the
micrometer before described marked, as stated, with radii of a circle r, a
spiral lines, the coils of which are equidistant, and a circle c graduated upon
the glass, and has also a moveable vernier n. It is usually accompanied by a
reticular thread moveable in a circular direction to the extent of at least one
hundred and eighty degrees. The micrometer may have two movements, one
a movement of displacement from its centre by means of the female screw or
pulley E screwed upon the rod B furnished with the improved "screw guides,"
and one of rotation upon itself. The needle A parallel to the body of the
instrument, shews upon a dial the amount of displacement, and the rotary
movement of the micrometer is measured upon another graduated circle
placed around the instrument. The needle A and its dial may be placed per-
pendicularly to the body of the instrument. The "reticula" and the diameter
A, B, of the micrometer may always be placed in such a manner that they may
make an angle of some kind, and the divided circle and vernier may act as a

page_text: graduated arc, from which sines and cosines, tangents and co-tangents, &c. may
be read also without displacement: the dimensions of the object may be reckoned
by its contact with the spire at a given point. This micrometer will give imme-
diately not only the precise dimensions of the object, but also serve for the easy
solution with the help of the recticula of trigonometrical problems. It may be
placed in front of the object glass, or between the object glass and the eye-
piece, or behind the eye-piece. Fig. 24 represents the optical part of a celestial
telescope. The object glass with a very short focus is composed of three groups,
A, B, C, formed each of the layers indicated by the letters p, q. r, s, t, u, v,
for the group A; a, b, c, d, for the group B: i, j, k, l, m, n, o. for the group C.
The arrangement, curves, and substances may be such that this object glass
thus combined shall not have any spherical aberration, nor any chromatic or
distorsive aberration. At a short distance from the focus is placed a
slightly divergent lens M, for the purpose of correcting when necessary the
rest of the aberrations, also to carry the focus to f. and to conduct the rays
of light on to the eye-piece under the same conditions as if the object glass L
had a very long focus, and was placed very far from the eye-piece. The
divergent lens is moveable, and may be set at any distance from the object
glass. The object glass may, if thought desirable, be made in two separate
parts more or less separated from each other, as will be seen at Fig. 30.
These arrangements allow, of telescopes being constructed with object glasses
of very short focus, but with great magnifying power, and thus a telescope
although of equal diameter and magnifying power shall be only one-third the
length, or less than that of good telescopes constructed on the ordinary plan.
Fig. 25 represents the ocular parts of a diminishing or magnifying eye-glass;
Figures 26, 27, 28, and 29 shew the ocular parts of various terrestial
telescopes constructed according to the same principles as the preceding, as
will be readily seen. The object glass formed of layers and groups may have
a periscopic form as well for terrestrial and astronomical purposes as for
photographic apparatus. This mode of construction by superposed layers may
be applied to the construction of all kinds of lenses or optical glasses. Their
mode of manufacture will be hereafter described.
In Sheet V., Figures 1, 2, 3, 4, 5. and 6 represent various views of a
binocular telescope. either for terrestrial or astronomical purposes, with a single
object glass, the eye-glasses of which admit of adjustment to varying distances,
so as to suit the eyes of the person using it. The focussing is effected by
means of the tube J', the female screw E. and the screw guides on the
tube T, and also by the female screw E acting upon the whole of the
parallelogram, and through it actuating the tube t. The tubular pieces

page_text: which form the support for the female screws E and E', and the screw V, &c.
are united with the tube T in the tube K, and thus partakes of all the move-
ments of the female screw E upon the screw guides y. On turning the
screw V the two pieces N which carry the "revolving holders of the inverting
glasses and eye-glasses, as shewn at Fig. 11. Sheet IV., will be caused to
approach or recede from each other to a distance suitable to the eyes of the
observer. The luminous rays come from the object glass upon the two prisms
or reflectors p. p. which carry them back to the prisms p'. p', which again
reflect them to the eye-glasses. Fig. 2 shews the form of the tubes N, N,
and of the links b, b; Fig. 4 shews the positions of the. prisms: Fig. 3 is a
section taken in the line A, B, of Fig. 1: Figures 5 and 6 shew the female
screw and the guide rods q: Figures 7, 8, 9, 10, and 11, represent a
binocular telescope (either terrestrial or astronomical) having two large object
glasses, which are not cut away at their sides, as in the former instance, and
the eye-pieces of which are capable of being set at varying distances apart by
means of a parallel motion. The focussing may be effected by means of a
quick frictional motion with the tubes J, or by the tubes T and the racks and
pinions i, i, mounted on the double-headed rod d, and also as in the telescopes
above described by the female screw E. The rays of light coming from the
object glasses on the prisms p pass through the prisms and the
inverting glasses to the eye-glasses mounted upon the frame N. as in the
preceding Figures. The two frames N upon which the prisms p' are fixed
are cansed to approach or recede from the prisms p as in the preceding
telescopes. The prisms may also be arranged as in Figures 1, 6, 9, Sheet III.
The coiled spring u has for its object to prevent the light or dust from
entering the instrument through the oval opening by keeping them her-
metically closed with small oval plates. Fig. 11 represents the stop bolt A of
the screw e before mentioned.
The working of these several apparatus will be clearly seen from the
accompanying Drawings without further explanation, as they are only modi-
fications of the binocular microscope first described with one or more object
glasses. Fig. 12 represents a telescope on the Newtonian principle, with a
parabolic speculum y. either silvered or platinized, the focus of which is only
two or three times the length of its diameter. Near the prisms p' is placed
the periscopic divergent meniscus lens M. which carries the focus to f.
This meniscus lens may also be placed before the prism p, as will be seen at
Fig. 13, if thought desirable. The prism p may also be placed beyond the
focus f, as will be seen in one of the arrangements shewn in Fig. 18. The
periscopic lens instead of being divergent might also be slightly convergent,

page_text: hut in this case it must be placed near the focus f, as will be seen at Fig. 14;
or the prism or reflector p may be placed in the front of the focus, as at
Fig. 15 or behind it, as in one of the arrangements of Fig. 18. the meniscus
convergent lens M of which is shewn in dotted lines. The divergent
periscopic lens is also applied to the opening of the telescope tube for the
purpose of causing the luminous rays to diverge sufficiently that the spherical
aberration of the reflector y may be compensated, and that all the rays may
cross each other at a mathematical point in the focus f.
Figures 17, 18, 19, and 20 represent the optical arrangements of three
forms of binocular telescope. The details of the mountings and movements
are omitted, as the Figures from 1 to 23. Sheet IV.. represent the telescopes.
and are sufficient to give an exact idea of their form. The revolving holders
shewn in Fig. 11, Sheet IV.. and the adjustable eye-glasses, shewn in Figures
16 and 17, Sheet II.. may be applied to these instruments, as also the arrange-
ments of meniscus lenses, short focus reflectors .y. and adjustable binocular
tubes; these various improvements, may be applied to Gregory's, Cassegrain's
or to other telescopes.
In order to make the small, microscope lenses.. especially for the first or
object glasses as well as the eye-glasses of the others. liquid glass is placed in
a small pot or crucible formed as shewn in Figures 22 and 23. The vitreous
matter is passed through a small opening o, and by means of a blowers it is
blown in a state of fusion; by this means it is granulated or divided into
round granules, the size of which is in proportion to the size of the opening o
and of the blower, and to the force with which the air or gas is projected
through the fused material. Instead of air or gas high pressure and super:
heated steam may be employed, or a stream of water or other liquid at a high
pressure and at a suitable temperature. If these granules should be required
to be slightly flattened on one side a plate of metal or glass is placed in front
and perpendicularly or obliquely to the plane of projection; they are then col-
lected in hot water or any other non-inflammable liquid, or in any other
manner, and annealed or fired if need be, and achromatized in the manner
hereafter to be described; there may be any number of openings o and also
of blowers that may be thought desirable.
The following are the processes for manufacturing the improved lenses with
concentric layers having variable refractive and dispersive powers from the
centre to the edges, and which process is applicable to the manufacture of
lenses of any form and dimensions. spherical, parabolic, elliptical, and hyperbolic,
concave, or convex.-By means of the apparatus represented at Fig. 24 the

page_text: form and thickness of the lenses from the centre to the edge and their curves
may be varied at pleasure according to the degree of density or liquidity of
the glass. This apparatus, as will be seen on, reference to the Drawing, is
composed, first, of a hollow fixed foot carrying the bell-shaped vessel made
of fire-brick, and having openings for the pipes t, t¹, into its interior for con-
ducting hydrogen or other gas and condensed air into the blow pipe c, at the
orifice of which they are ignited; second, of a shaft B, which may be driven
at a rapid speed by means of the pulley P in communication with friction
gearing it carries a capsule or cup g made of platinum or fire-clay. This
cup may be either concave, as in Figures 24 and 25, or convex, as in Fig. 26.
or of any other form, according to the form of lens required to be produced.
A drop or lump of liquid glass is to be placed upon the cup g, the apparatus
is set in motion, and when one layer has received the required form the fire
is moderated and the apparatus stopped and the second layer of liquid glass
of the same or of different density is laid thercon, and the operation is con-
tinued as before, and so on until the lens has been brought to the required
form, thickness, and density. The various vitreous matters in fusion may be
taken from the pots (placed in the furnace for that purpose) with a platinum
brush, the handle of which is hollow, and through which ignited air and gases
are caused to pass into the wires of the brush, so that the matter being kept
at the required temperature has not time to solidify, and may be laid upon
the lens placed upon the preceding apparatus when stationary in the same
manner as a layer of any other substance such as paint would be laid on.
Plates of suitable thickness and forms in crown and flint glasses may also be
prepared by blowing and moulding, as hereafter described, and caused to
adhere together; for this purpose the arrangement of tubes t; t', (Fig. 24)
is employed fed by air and hydrogen gas or any other combustible giving a
flat fan-shaped flame. Pincers having two or three jaws are held in each
hand for the purpose of holding the plates to be united; when the faces to be
united have been softened they are brought in contact through the flame, the
pincers being continually kept turning. In the case of periscopic convex
plates, the one which is to take the form of the other must be softened on
both faces. The handles of the pincers and also that of the platinum brush
have a tube like that of the blow pipe c for the passage of air and gas which
passes through them, the flame impinging upon the back of each plate at the
same, time, that the flame of the intermediate burner impinges upon the two
faces; this arrangement allows of one of the plates being sufficiently softened
to take the form of the other.

page_text: If the plates are of somewhat large dimensions the pincers are mounted
upon a lathe to the mandrils of which a rotary motion of greater or less speed
is imparted, and also a reciprocating motion. One of these shafts may advance
one of these two plates upon the other; seams and inequalities are caused to
disappear by the softening of the glass combined with the motion, but if the
lenses to be produced are of large dimensions the preceding processes might
be partly insufficient, and in that case plates are employed of the dimensions,
forms, thickness, and refractive and dispersive powers suitable for the effect
desired to be obtained. They are laid over one another one by one. and set
in a mould of polished clay which is introduced into an annealing oven and
left there until the plates all adhere. If the lens is to be of any other form
than plano-convex the mould has a heavy cover glazed inside, which bearing
upon the lens imparts to it the form (either convex or concave), which it has
itself. A greater or less degree of pressure may be employed in order to
expedite the adherence and increase the density. If seeing the various kinds
of glass (crown and flint) employed fluid or in plates, and seeing the curves
of the lens and the length of focus which might be required, achromatic lenses
free from aberrations of any kind could not be obtained. groups might be
employed formed of layers superposed and afterwards united as simple plates.
If required fluxes might be interposed between the plates or upon the exterior
surfaces of the lenses with the platinum brush. These fluxes may be composed
as follows;-One part of white sand, three parts of minium, 0.5 of calcined
borax, or three parts of white sand, one part of minium, and five parts of
calcined borax, or others according to the effect desired to be obtained. Instead
of these fluxes pulverized glass (either flint or crown) is employed especially
upon exterior plates, by means of the fan-shaped burner; this powder is brought
into a state of fusion and the required form is given to it by a suitable move-
inent. Bevilled plates which are partially superposed or concentric circles and
plates, the bevils of which overlap, may be employed, so that the index of
refraction shall vary from the centre to the edge. Instead of these circles
or plates or concurrently with them annular parcels or fagots of glass threads
of flint or crown glass of various densities are placed concentrically one in the
other, and superposed or not at their extremities. These circles or parcels of
threads are made of any thickness, and are shewn at Figures 35, 36, and 37;
the threads of glass may also be placed vertically, as seen at Fig. 34, which is a
packet of glass thread arranged. in a cylindrical form and afterwards annealed.
The refraction and dispersive power is also caused to vary in lenses, the density
of which is variable from the centre to the edge by placing tubes formed of

page_text: glass of different densities, as flint and crown glass. Figures 29. a, b, c. d. one
inside the other, which are softened by heating and again blown. Other tubes
of greater density f, g, h, i, Fig. 30, are placed inside them, softened and
again blown. Tubes j, k, 1. (Fig. 31) are again put in until the whole and
the centre are well filled, they are again softened and drawn, and a cylinder
like that shewn at Fig. 33 is obtained. If drawn with sufficient rapidity the
whole of the concentric cylinders, Fig. 31, will only form a single cylinder of
greater or less thickness, Fig. 32 or Fig. 33. or if the cylinders interposed are
sufficiently numerous a convex lens cut from this cylinder will be deprived of
spherical aberration and even of chromatic aberration if the density augments
from the edge to the centre, if concave it will be also deprived of aberration,
if the density augments from the centre to the edge. These tubes brought
at their extremity to the point of fusion may be blown and microscope lenses
will be formed that will be in concentric layers and will be achromatic and
without aberration. By bringing them to the point of fusion lenses may in
this manner be produced, the outer layers of which will be less dense
and have the form and arrangement of layers analogous to those of the
crystalline lens of the human eye and will be achromatic (sec Figures 27 and
28). Under certain circumstances concurrently with the plates, circles.
bundles, and fluxes, silicates in solution in hydrochloric acid or hydrofluoric
acid may be employed diluted with water or combined with other transparent
substances either to cause the plates to adhere together or to obtain the required
degree of refraction or dispersion. Intermediate layers of crystallized boron
sesquichloride of carbon, crystallized or melted silicic acid. bichloride of tin,
small crystals, and even powder of any kind, principally powdered glass, either
colorless or of many colors, obtained by the method of granulation above
described, are applied by means of heat and pressure, currents of electricity,
and other mechanical and chemical forces aided by blowing, moulding, and
motion. By these means all the required forms and qualities are obtained, so
that the refrangibility, dispersion, transparence, malleability, density, hardness,
and elasticity of these lenses may be varied.
Having now described the nature of this Invention, and explained the
manner of carrying the same into effect as communicated to me by my foreign
correspondent. I desire it to be understood that under the above in part recited
Letters Patent. I claim.-
First, the general arrangement and construction of parts herein shewn and
described, and constituting what the Inventor denominates a universal
microscope.

page_text: Second, the rotary micrometer shewn at Figures 1, 10, and 11. Sheet I..
and Figures 21. 22. and 23, Sheet IV., and applicable to various optical
instruments.
Third, the arrangement and construction of parts herein shewn and described
applicable to binocular optical instruments.
Fourth, the use and application to optical instruments of an object glass or
glasses, composed of a combination of lenses as herein shewn and described.
Fifth, the various arrangements of parts herein shewn and described and
modes of constructing telescopes and other analogous optical instruments.
Sixth, the mode herein set forth of manufacturing lenses for optical instru-
ments by the combination of glasses of different densities, qualities, or colors.
Lastly, claim the different arrangements of parts herein shewn and
described and the applications thereof to the various optical instruments herein
referred to.
In witness whereof, I, the said Henry Edward Newton, have hereunto.
set my hand and seal, the Thirteenth day of August, in the year of
our Lord One thousand eight hundred and sixty-six.
H. E. NEWTON. (L.S.)