Microscopes and Accessory Apparatus Part 9

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 gla.s.splate 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.

[Ill.u.s.tration: 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=

[Ill.u.s.tration: Dissecting Stage No. 57. With Lens No. 71.]

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

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

[Ill.u.s.tration: Simple Dissecting Microscope No. 58a.]

58a. =Simple Dissecting Microscope=, consisting of a wood case with plate gla.s.s 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=

[Ill.u.s.tration: 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=

[Ill.u.s.tration: 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.

[Ill.u.s.tration: Doublet No. 70.]

[Ill.u.s.tration: Doublet No. 71.]

[Ill.u.s.tration: 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.