Part 3

9. =Medium Size Microscope=, inclinable, coarse adjustment by rack and pinion, fine adjustment by micrometer-screw. Draw-tube with millimetre scale. Illuminating apparatus and iris-diaphragm with lateral screw for raising and lowering. A ring under the iris diaphragm serves to hold a ground glass or colored disc. The illuminating apparatus and cylinder diaphragm are easily interchangeable. Triple nose-piece. Objectives 3, 6, Oil-Immersion 1/12, N. A. 1,30. Eye-pieces I, III, IV. Magnifications 60--1000 =120.--=

10. =The same= with Illuminating Apparatus. Triple nose-piece. Objectives 3, 6, Oil-Immersion 1/10, N. A. 1,30. Eye-pieces II, IV. Magnifications 70--730 =108.--=

11. =The same= without Illuminating-Apparatus. Triple nose-piece. Objectives 3, 6, 8. Eye-pieces I, III. Magnifications 60--550 =84.--=

12. =The same= without Illuminating Apparatus. Double nose-piece. Objectives 3, 7. Eye-pieces I, III. Magnifications 60--450 =66.--=

13. =The same= without Illuminating Apparatus and nose-piece. Objectives 3, 7. Eye-pieces I, III. Magnifications 60--450 =60.--=

=Stand= with Illuminating Apparatus and Iris-diaphragm, without objectives, eye-pieces and nose-piece =48.--=

=The same stand= with Cylinder Diaphragm =38.--=

=Cylinder iris-diaphragm= (Cf. p. 23) =6.--=

=Stand IIb.=

14a. =Medium Size Microscope=, stand inclinable to the extent of 45°, tripod foot, coarse adjustment by rack and pinion, fine adjustment by micrometer screw. Draw-tube with millimetre scale. Illuminating Apparatus and Iris-diaphragm permanently connected and sliding in a sleeve underneath the stage. The cylinder-diaphragm is used in the same manner. A ring below the iris-diaphragm serves to hold a ground glass or colored disc. Triple nose-piece. Objectives 3, 6, Oil-Immersion 1/12, N. A. 1,30. Eye-pieces I, III, IV. Magnifications 60--1000 =104.--=

14b. =The same= with Illuminating Apparatus. Triple nose-piece. Objectives 3, 6, 8. Eye-pieces II, IV. Magnifications 70--700 =78.--=

15a. =The same= without Illuminating Apparatus. Double nose-piece. Objectives 3, 7. Eye-pieces I, III. Magnifications 60--450 =50.--=

15b. =The same= without Illuminating Apparatus and nose-piece. Objectives 3, 7. Eye-pieces I, III. Magnifications 85--450 =44.--=

=Stand= with Illuminating Apparatus and Iris-diaphragm =32.--=

=Stand= with Cylinder or Wheel-diaphragm =22.--=

=Cylinder iris-diaphragm= (p. 23) =6.--=

For the addition to this microscope of a lateral screw for raising and lowering the illuminating apparatus as on Stand IIa, an extra charge of $2.-- is made.

=Stand III.=

Stand III is now provided with rack and pinion coarse adjustment instead of sliding tube. In consequence a nose-piece can be used on it to better advantage. It will be found an excellent laboratory stand at low price.

16a. =Medium Size Microscope=, non-inclinable stand, coarse adjustment by rack and pinion, fine adjustment by micrometer-screw. The draw-tube has a millimetre scale. Plane and concave mirror. Wheel-diaphragm. Triple nose-piece. Objectives 3, 6, 8. Eye-pieces I, III. Magnifications 60--550 =66.--=

16b. =The same= without nose-piece. Objectives 3, 6, 8. Eye-pieces I, III. Magnifications 60--550 =58.--=

17a. =The same=, with double nose-piece. Objectives 3, 7. Eye-pieces I, III. Magnifications 60--450 =48.--=

17b. =The same= without nose-piece. Objectives 3, 7. Eye-pieces I, III. Magnifications 60--450 =42.--=

=Stand= with wheel-diaphragm =20.--=

=This stand= can be supplied with iris diaphragm in stage (see illustration p. 23) instead of wheel-diaphragm.

=Stand= with iris diaphragm =26.--=

=Stand IV.=

The dimensions of this stand are now larger than formerly. The price has not been changed.

18. =Small Microscope.= Adjustable by sliding tube and micrometer-screw. The draw-tube is graduated in millimeters. Cylinder-diaphragm with sliding sleeve. Concave and plane mirrors, obliquely adjustable. Objectives 3, 6, 8. Eye-pieces I, III. Magnifications 60--550 =52.--=

19. =The same.= Objectives 3, 7. Eye-pieces I, III. Magnifications 60-450 =36.--=

20. =The same= without Cylinder Diaphragm, with Wheel Diaphragm. Objectives 3, 5, 7. Eye-pieces I, III. Magnifications 60--450 =44.--=

21. =The same.= Objectives 1, 3, 7. Eye-pieces I, III. Magnifications 18--450 =40.--=

22. =The same.= Objectives 3, 7. Eye-pieces I, III. Magnifications 60--450 =34.--=

=Stand= with cylinder-diaphragm, without objectives and eye-pieces =14.--=

=Stand= with wheel-diaphragm, without objectives and eye-pieces =12.--=

=Stand V.=

23. =Small Microscope=. Adjustable by sliding tube and micrometer-screw. Concave mirror. Objectives 3, 7. Eye-pieces I, III. Magnifications 60--450 =30.--=

24. =The same.= 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.--=

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.=

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.--=

=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=

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.--=

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.

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.--=

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.

=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.--=

=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.=

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=

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.--=

=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.

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=

57. =Dissecting Stage= with white glass plate and moveable lens-holder--without lens =2.--=

58. The same with lens No. 71 =3.25=

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=