Objectives 3, 5.
Eye-pieces I, III.
Magnifications 60--250 =28.--=
25. =The same.= Plane mirror.
Objectives 1, 3.
Eye-pieces I, III.
Magnifications 18--80 =24.--=
26. =The same.=
Objectives 3.
Eye-pieces I, IV.
Magnifications 60--105 =18.--=
27. =Stand= without objectives and eye-pieces =8.--=
[Illustration: Stand VI.]
28. =Auxiliary Laboratory Stand=, for the examination of
trichinae and for searching plate cultures. Very large
stage (3-1/2×4 inch.). Adjustable by means of a carefully
constructed rack and pinion, rendering it possible to
focus objectives of fairly high power.
=Stand=, without eye-pieces, objectives or case =8.--=
29. This stand fitted with objective 3, eye-pieces 0 and
IV. Magnifications 40 to 100, in mahogany case fitted
with lock =18.--=
29a. =The same stand= fitted with eye-piece II and
objective having separable front lens, yielding a
magnification of 40 and 100 diam =18.--=
=Glass compressor= with graduation =--.80=
=Glass compressor= without graduation, per pair =--.40=
=Demonstration microscope.=
[Illustration: Demonstration microscope with condenser.]
30a. Adapted for low and medium power. Square stage
with wheel-diaphragm.
Adjustment by sliding tube; after being adjusted
the tube may be fixed by a ring clamp. Detachable
handle.
With clip to hold a sketch or label, etc. Stand
without objective and eye-piece. =6.--=
30b. =The same= with objective 3 and eye-piece I,
magnifying 60 times =14.--=
30c. =The same= with adjusting screw for focussing high
power objectives, with condenser and iris-diaphragm,
without objectives and eye-pieces =18.--=
30d. =The same= with objectives 3 and 6 and eye-piece I.
Magnifications 60 and 255 =38.--=
[Illustration: Nebelthau's Sliding Microscope.]
=Nebelthau's Sliding Microscope.=
(Cf. Zeitschrift für wissenschaftliche Mikroskopie, XIII, 1896.)
31. The sliding microscope is an instrument by means of
which very large microscope sections, as, for example,
large sections of the brain, can be systematically
examined. It is also of service in looking over plate
cultures of bacteria.
The microscope is carried on a heavy beam supported
by two stout pillars under which the stage
moves. The various movements are accomplished by
motion of the microscope on a lateral track upon
its support and by motion of the stage on a similar
track at right angles to the first. The motion of the
microscope is by means of a screw, that of the stage
by double rack and pinion. The extent of the movements
is indicated in each case by a scale, thus
permitting the systematic examination of the entire
specimen.
The stage consists of a glass plate, measuring
16×20 cm, which is carried in a frame supported on
four columns. The tracks permit a motion of the
microscope of 18 cm and of the stage of 13,5 cm. A
mirror under the stage affords ample illumination.
The microscope tube is so arranged that it can be
easily removed from the stand and a simple lens substituted
for it. The coarse adjustment of the microscope
is by rack and pinion. A screw above the objective
serves for fine adjustment. The price of this sliding
microscope, without objectives or oculars, but with a
lens holder and simple lens magnifying eight diameters
is =80.--=
=Flat glass dish= of the same size as the stage to hold
very large sections for the purpose of examining them
while in clearing fluid =1.25=
[Illustration: Dölken's Microscope stand.]
32. =Dölken's Stand.= (p. 52) The stand is larger than
Stand No. Ia, but is modified as shown in the cut so as
to permit the examination of unusually large
preparations. It is provided with the illuminating
apparatus b (p. 22) and with all the adjustments
necessary to the use of high powers.
=Stand= and illuminating apparatus, without nose-piece =80.--=
[Illustration: Travelling Microscope No. 33.] $
33. =Travelling Microscope.= This microscope is ready for
use after spreading the foot, drawing out the tube and
setting the mirror and stage in position. It is provided
with all the adjustments of Stand No. V, consisting of
fine adjustment by micrometer-screw, coarse adjustment
by rack and pinion and illuminating apparatus d (p. 22).
The box is arranged so as to accommodate three
objectives and two oculars. It locks, has a handle, and
measures 25×15×7 cm, the whole apparatus weighing 5
pounds.
Price of this microscope with illuminating apparatus,
but without objectives or oculars =32.--=
=The same=, without illuminating apparatus =24.--=
[Illustration: Large Travelling Microscope No. 34.
(Size of mahogany case 28×19×8 cm.)]
This instrument (in size like the Ib.) combines all the essential
features of a large laboratory microscope with a folding stand. It will
be found invaluable on scientific expeditions, for research work etc.
When lifted out of the case, spread the two parts forming the base,
which are then held by a spring-catch. After raising the tube, turn the
stage around and tighten it by means of a lever. It is supplied with
large Abbe condenser and Iris diaphragm adjustable by side screw. Coarse
adjustment by rack and pinion, fine adjustment by micrometer-screw.
Graduated draw-tube. The stand has joint for inclination.
[Illustration: Large travelling microscope No. 34 (set up).]
34. =Stand= with Abbe Condenser and Iris-Diaphragm, double
nose-piece =66.--=
35. =The same=, with objectives 3, 6, Oil-Immersion 1/12",
N. A. 1,30. Eye-pieces I, III. Magnifications 60--800 =128.--=
[Illustration: Horizontal-Microscope.]
36. =Horizontal Microscope.= This instrument consists of
a microscope tube placed horizontally on a long
extensible column, supported in turn by a tripod base
provided with levelling screws and a round spirit level.
The extension of the upright supporting column is
accomplished by two sliding motions, the lower,
controlled by a set screw only, being intended for
coarser adjustments, the upper, controlled by rack and
pinion, for finer adjustments. A millimeter scale and a
vernier serve to indicate the degrees of the various
motions, so that vertical motion of the microscope tube
to the extent of 1/10 mm may be accomplished.
The microscope tube carries a spirit level and revolves
upon a horizontal disc. The objective, consisting of two
separable doublets, permits three degrees of
magnification of 5, 9 and 48 cm focal distance
respectively. A rack and pinion adjustment serves as
adjustment of the microscope tube. A micrometer, 1 cm
long and divided into 100, in the diaphragm of the
ocular still further increases the availability of the
instrument for making fine and accurate measurements.
The instrument serves as a useful aid in many physical
and physiological investigations.
Price, including objective, ocular and micrometer =40.--=
=Microscopes for Mineralogical Research.=
We construct two Microscopes for mineralogical investigations. Both are
adapted for determining the axes of elasticity and for the
differentiation of isotropic and anisotropic bodies. Stand I alone is
adapted for determining the optical axes and their angles.
Only such objectives, condensers and oculars are available for
mineralogical examinations as have been shown after careful examination
in polarized light to be free from polarization.
[Illustration: Mineralogical Stand I.]
=Mineralogical Stand I.=
37. This microscope corresponds in its dimensions to
Stand Ia as described on page 31. Coarse adjustment by
rack and pinion, fine adjustment by micrometer-screw,
the milled head of which has 50 divisions, each
representing a motion of the objective of 1/100 mm. The
condenser, iris-diaphragm and polarizer can be raised
and lowered by rack and pinion. A triple condenser
facilitates the observation of the axial lines in the
microscope. It is so arranged as to be easily replaced
by a simple diaphragm-carrier. By means of a collar
attached to the end of the tube the objective is brought
into coincidence with the centre of the revolving stage.
This revolving stage is divided into 360 degrees and
fitted with a vernier and index. Two scales on the
stage, at right angles to each other, permit accurate
location of specimens. The Nicol prism, which serves as
a polarizer, can, after turning the iris-diaphragm
aside, be drawn out from under the latter. The zero
position of the Nicol prism is indicated by a line, as
well as the angles 90, 180, 270°. The analyser is
mounted in metal and is firmly fixed above the eye-
piece. The analyser rotates on a disc graduated to 360
deg. The front of the tube has a movable window which
provides access to the inner tube. In the latter is an
opening for the introduction of a Bertrand lens. This
lens serves the purpose of magnifying the interference
figures produced by the converging rays of polarized
light. This lens and the eye-piece can be raised or
lowered by rack and pinion. In the analyzer is a slide
for the insertion of gypsum and quartz plates at an
angle of 45 degrees.
In many investigations it is advisable to employ an
analyzer introduced laterally into the tube, instead of
the one mentioned above.
The following parts are supplied to complete the outfit:
Triple nose-piece.
Eye-piece 0, with Bertrand's quartered quartz plate.
Eye-piece I with cross-lines, Brezina's Calcspath-plate,
cleft perpendicularly to its axis, made to fit over
eye-piece I, Klein's gypsum and quartz plates for
insertion in the opening over the objective.
Price of the stand with these accessories =160.--=
38. =The same= with eye-piece III, objectives 1, 3, 5, 7.
1/12 Oil-Immersion, magnifications 18--800 =236.--=
The new mechanical stage No. 98 (See page 78) can be
fitted to the stand for the purpose of investigating
large preparations and serial sections.
Price =28.--=
[Illustration: Mineralogical Stand II.]
=Mineralogical Stand II.=
39. The base and pillar are in one piece, neatly
japanned black. The coarse adjustment is by rack and
pinion.
The stage is revolving and graduated on the edge into
360 degrees. A pointer indicates its position.
The polarizer has stop at zeropoint and also marks at 90°,
180° and 270°. It is held in a spring-sleeve and the
substage can be raised and lowered by lateral screw, or
may be swung to one side. The condenser is mounted in
separate arm above the polarizer and swings out of the
optical axis by means of a lever, if parallel instead of
convergent rays are desired.
The analyzer fits into an opening of the tube above the
objectives and can be instantly thrown in or out of the
optical axis. There is a slot below the analyzer for the
insertion of quartz and gypsum plates.
By means of a collar with two centering screws attached to
the end of the tube, the objective may be brought into the
optical axis.
Price of this microscope with eye-piece I with cross-lines,
Klein's quartz wedge and gypsum plate, red, I. order
=$56.--=
40. =The same= with eye-piece III. and objectives 3 and 5.
Magnifications 60-250 =74.--=
=Dissecting Microscopes and Hand Lenses.=
[Illustration: Large Dissecting Microscope No. 41.]
41. =Large Dissecting Microscope.=
Stand on heavy horse-shoe base, large stage with glass
plate, adjustment by rack and pinion. The lens-carrier
is movable for examining large plates. Illumination by
movable plane mirror and white glass plate. Metal hand-
rests covered with leather may be attached to the sides
of the stage. They fit inside the mahogany case.
A black metal plate with wheel-diaphragm or a milk-
glass-plate can be inserted below the stage, serving as
dark or white back-ground respectively.
Stand without lenses in mahogany case =16.--=
42. =The same= with three aplanatic lenses after
Steinheil, magnifying 8, 16 and 20 diameters =28.--=
43. =The same= with these lenses and Abbe's drawing
apparatus =40.--=
44. =The same stand= with prism-tube No. 49 for erected
image. Objectives 1*, 2, 3, magnifying 18, 40 and 80
diam. =47.25=
[Illustration: Simple Dissecting Microscope No. 45.]
45. =Simple Dissecting Microscope=, with adjustment by
rack and pinion, movable plane mirror and white glass
plate, glass stage in metal frame. Metal hand-rests
covered with leather fit inside the case. Stand without
lenses =8.--=
46. =The same= with two aplanatic lenses after
Steinheil, Magnification 10 and 20 diam. =16.--=
47. =The same stand= with prism-tube No. 49, for erected
image; with objectives 2 and 3, magnifying 40 and 80
diam. =36.--=
[Illustration: Dissecting microscope with erected image after R.
Pfeiffer.]
=The Dissecting microscope with erected image according to Prof. R.
Pfeiffer= has been constructed in such a way that all parts extending on
both sides can be folded or turned, so that the instrument fits in a
very small case.
The base consists of two parts which may be folded. The stage can be
brought in a position vertical to the optical axis and the metal hand
rests laid on top of the stage. They are connected with the latter by
joints. The mirror can also be turned and put parallel to the pillar.
A round glassplate is set in the stage, below which is an iris diaphragm
to properly regulate the illumination.
The adjustment is by rack and pinion.
Two rightangle prisms are mounted inside the tube in such a manner that
the image obtained by the objective is reflected into the eye-piece and
appears erected.
The eye-piece is of the Ramsden form. Three objectives of different
magnifying power with specially long working-distances have been
constructed Nos. 1, 2, 3.
The following table shows the magnification of the
objectives in connection with the eye-piece.
Objective 1 2 3
Magnification 18 40 80 diam.
Working distance 58 mm 18 mm 6 mm
Prices:
48. Folding dissecting microscope, stand only =24.--=
49. Upper part of the microscope, consisting of tube
with prisms, and one eye-piece =16.--=
50. Objectives 1, 2, 3, a $ 6,00 =18.--=
---------
51. Stand with complete outfit =58.--=
The instrument is furnished in a mahogany case with
nickelplated handle, lock and key.
[Illustration: No. 52. No. 53. No. 54.
Lens-holders.]
52. =Lens-holder= on iron foot with moveable arms, the
joints of which may be fixed by thumb-screws, rack and
pinion adjustment--without lens =7.20=
53. =Lens-holder=, nickel-plated stand with attachment
of the collar holding the lens by ball and socket joint =4.--=
54. =Lens-holder= on heavy iron foot, ball and socket
joints, adjustable to any position--without lens =3.25=
55. =Pocket microscope.= The size of an eye-piece, in box =3.25=
56. =Lens= for examining Algae =1.25=
[Illustration: Dissecting Stage No. 57. With Lens No. 71.]
57. =Dissecting Stage= with white glass plate and moveable
lens-holder--without lens =2.--=
58. The same with lens No. 71 =3.25=
[Illustration: Simple Dissecting Microscope No. 58a.]
58a. =Simple Dissecting Microscope=, consisting of a
wood case with plate glass stage, movable plane mirror,
two simple lenses of 4 and 8 times magnification. Price =2.--=
58b. =The same= with metal hand rests, moveable lens-holder
and doublet magnifier No. 71, Price =3.50=
[Illustration: Demonstration lens-holder No. 59. Focussing-lens
Handle No. 61. No. 60.]
59. =Demonstration lens-holder=, consisting of a
hardrubber stage with handle, clamps for holding the
preparation in position, and with a moveable lens-
holder. Without lens =2.40=
60. =Focussing lens= for photographic camera. Lens in
spring-sleeve with clamping ring =4.75=
61. =Handle= with ring for holding lens =1.25=
[Illustration: Steinheil lens No. 63. Steinheil lens No. 66.]
The =aplanatic triplets after Steinheil= are remarkable
for their large, flat field and excellent definition,
free from chromatic aberration.
Diameter Visual field Magnification
62. 24 mm 20 mm 8 diam. =4.--=
63. 15 " 15 " 10 " =4.--=
64. 12 " 12 " 12 " =4.--=
65. 10 " 10 " 16 " =4.--=
66. 6 " 3,5 " 20 " =4.--=
67. 5 " 2 " 30 " =4.--=
68. 3 " 1 " 40 " =4.--=
The =achromatic doublets= have a very large, clear and
flat field.
69. 30 mm 35 mm 5 diam. =4.--=
70. 23 " 20 " 8 " =3.25=
=Doublet magnifier=, consisting of two double convex
lenses.
71. 23 mm 25 mm 6 diam. =1.25=
The doublet No. 69 can only be used as a hand lens. The
mounting of all the other lenses is such that they fit
any of the dissecting stands or lens holders. Aplanatic
triplets 64-68 can only be used on stands with rack and
pinion adjustment.
[Illustration: Doublet No. 70.]
[Illustration: Doublet No. 71.]
[Illustration: Pocket lens No. 72.]
72. The aplanatic lenses Nos. 62-66 are also to be had
with a moveable cover and ring adapting them for use as
pocket lenses.
Price, when thus mounted =4.75=
[Illustration: Binocular Preparation Microscope.]
73. =The Binocular Preparation Microscope=, after the
model of Eilhard Schulze permits the convenient use of
both eyes in dissecting small anatomical and botanical
preparations. It consists of two Brücke lenses, adjusted
to an accurate focus.
Both tubes are moveable on a joint and are adjustable to
various distances between the observers eyes. The
distance of the eye from the preparation is about 250
millimetres; the field of vision is large and flat; the
magnification, four diameters; lenses are adjustable to
either vertical or horizontal position and may be raised
and lowered on the vertical support, thumb-screws fixing
them in the desired position. A rack and pinion serves
as fine adjustment =24.--=
[Illustration: Greenough's Binocular Microscope.]
74. =Greenough's Stereoscopic Binocular Microscope.=
Two microscope tubes are so arranged as to bring the
same object into focus in the axis of each tube, the
tubes being set at an angle to each other for this
purpose. The stand is provided with rack and pinion
adjustment and both draw-tubes are also regulated by a
rack and pinion arrangement, so that they may be adapted
to the correct distance of the observers eyes.
By interposition of prisms the image is rendered erect.
Magnification, 20 diam. Price =80.--=
74a. =Corneal-Microscope=, is designed for the examination of
the interior of the eye.
=Prismtube= No. 49 with eye-piece =16.--=
=Objective= of low power permitting 2 degrees of
magnification =6.--=
=Stand= on heavy base, with rack and pinion adjustment
etc. =8.--=
-------
=30.--=
=Apparatus for Blood Examinations.=
[Illustration: Micro-Spectroscope.]
75. =The Micro-Spectroscope= fits into the tube of the
microscope like any ordinary eye-piece and may be fixed
in any desired position by means of the thumb-screw M.
The position of the bright and dark lines of the
spectrum and their respective wave lengths are
ascertained by means of a scale. The flat drum A, the
interior of which is shown in section, contains the slit
and the comparison prism. The slit is regulated by the
screws F and H. The lever T moves the comparison prism
across one half of the slit. The cylinder Q above the
eye-piece contains the Amici prism. At the point N of
the horizontal tube RN is the micrometer scale,
illuminated by the mirror O. After raising the spring-
catch L the upper part of the spectroscope may be turned
round the pivot K, thus allowing of the adjustment of
the eye-piece =66.--=
(A full description accompanies each instrument.)
76. =Hand-Spectroscope=, Browning's, for spectroscopic examination
of the blood =12.--=
76a. =Hand-Spectroscope= with comparison prism, mirror,
and holder for vials =16.--=
[Illustration: Thoma's Haemacytometer.]
77. =Thoma's Haemacytometer= consists of an object glass
with carefully constructed cell, a ground absolutely
plane coverglass and two pipettes for mixing the blood
and saline solution used in the examinations. One of
these pipettes, for estimating the number of red
corpuscles is so graduated as to permit dilution of the
blood 100 or 200 times as required; the other, for
counting the white corpuscles (leucocytes), is graduated
for dilution of the blood 10 or 20 times.
The volume contents of the pipettes are most carefully
determined and the depth of the cell is established by
accurate micrometric measurement, thus permitting very
exact observations by means of this instrument.
(A full description with each instrument) =14.50=
78. =Mixing-Pipette for white corpuscles= =3.60=
79. =Mixing-Pipette for red corpuscles= =3.60=
80. =Thoma counting chamber, with coverglass= =5.75=
81. =Türck counting chamber with coverglass= =7.25=
[Illustration: Counting chamber
after Thoma after Türck.]
[Illustration: Ehrlich's Eye-piece.]
82. =Ehrlich's Eye-piece= is provided with a diaphragm
having a square opening, the size of which is regulated
by a small lever.
This eye-piece is designed to facilitate the estimation
of the relative numbers of red and white blood
corpuscles in dry preparations.
Full directions accompany each instrument =12.--=
82a. =Apparatus= for the clinical determination of the
alcalinity of the blood, after Prof. C. S. Engel.
The following parts compose the apparatus:
1) a capillary pipette so graduated as to permit the
dilution of 0,05 cc. blood from the finger, up to 5 cc.
with distilled water.
2) a beaker, for the reception of the diluted blood.
3) a burette mounted on stand, capacity 10 cc. Full
directions accompany each outfit. Price in box =8.--=
=Micrometers.=
[Illustration: Screw Micrometer Eye-piece.]
83. =Screw-micrometer eye-piece= for accurate
measurement of large objects. Between the eye lens and
the collecting lens of a Huyghenian ocular there is a
millimeter scale etched on glass, above which is a
moveable indicator whose position is controlled by a
micrometer screw to which a graduated drum is attached.
The value of each graduation on the drum (about 1/20 of
the micrometer value of the objective) must be
determined for each combination of ocular and objective
by means of the stage micrometer. The eye lens of the
ocular is moveable to permit accurate focus upon the
scale. The apparatus slips into the tube of the
microscope like any ordinary eye-piece and is fixed in
position by a thumb-screw at the side =20.--=
84. =Micrometer eye-piece.= The mount unscrews in the
centre to permit the introduction of the micrometer
scale. The eye lens is moveable to permit of accurate
focus on the scale =4.--=
85. =Glass-Micrometer for the eye-piece=, to drop on the
diaphragm of the eye-piece. Scale of 5 mm divided into
100 parts =2.50=
86. =The same=, 10 mm divided into 100 parts =2.--=
87. =Stage-Micrometer=, 1 mm divided into 100 parts
etched on glass =3.75=
88. =Stage-Micrometer=, photographed on glass, 2 mm
divided into 200 parts =1.40=
89. =Eye-piece Micrometer=, divided into squares for
counting scattered objects in the field. Mounted.
Distance between the lines 0,5 mm =2.--=
90. =Glass slide with cell= 2/10 mm deep, with ocular
micrometer No. 89, in box =3.25=
91. =Glass slide with cell= the floor of which is
divided into squares, 1/400 square mm each, in box =4.--=
=Drawing Apparatus.=
The two following =drawing eye-pieces= Nos. 92 and 93,
have quickly found favor among those having frequent
occasion to make drawings from microscopic preparations
and are now largely used in educational institutions as
an aid to students in the study of their specimens. In
both eye-pieces the prism is so adjusted as to
accomplish total reflection of the image, thus doing
away with loss of light and with secondary reflections,
such disturbing features of those forms of drawing
apparatus of which a mirror forms an essential part.
[Illustration]
92. This =drawing eye-piece= is employed with the stand
in the vertical position. The reflected image lies at
the side of the microscope, the rays passing off at an
acute angle from the reflecting prism near the top of
the eye-piece. The eye-piece slips into the tube of the
microscope like any ordinary eye-piece and is held in
position by a thumb-screw. The drawing field is at once
visible without further adjustment, and the picture is
clear and sharp. The brightness of the drawing field may
be regulated by smoked glass plates mounted in two
moveable metal arms =8.--=
[Illustration: Drawing eye-piece for drawing with inclined stand.]