The revolving eye-piece is also particularly well adapted to use as a micrometer ocular, for when the eye lens is turned aside a micrometer scale may be inserted and rests upon the diaphragm of the eye-piece. Once adjusted in this way the micrometer values are the same for all the eye lenses of the combination.
| Prices: Double revolving Eye-piece, without eye lenses | $4.— |
| Each eye lens | $1.25 |
| Eye-piece Micrometer, No. 86 | $2.— |
Stands.
For the past thirty years division of labor has been employed to the utmost possible extent in the manufacture of our microscopes. This principle has been applied to our machinery as well as to our workmen, with the result that we have gradually accumulated a large plant of special machinery of the most accurate construction, each machine especially adapted to the manufacture of some particular part of our microscopes. By this development of mechanical appliances for microscope manufacture two ends have been attained:—The greatest accuracy and uniformity of construction of our microscopes has been made possible, while at the same time it has been possible to cheapen the cost of manufacture. Instruments which are the product of delicate machinery must always be more uniform, more accurate and should be less costly than those manufactured by hand.
In the following remarks we refer more particularly to the larger microscope stands of our manufacture and draw attention to those parts which should be present in every well equipped microscope.
The elements of these microscopes are:
1. The foot and upright support with joint for inclination,
2. The stage,
3. The sub-stage, with condenser, iris diaphragm and mirror,
4. The body with the adjustments,
5. The tube, carrying eye-piece, nose-piece and objectives.
1. The foot and upright support are solid and are of such weight and shape as to permit inclination of the body of the microscope to a horizontal position. The foot is horse-shoe shaped and is made to touch the table at three points, thus insuring stability even on a surface which is not entirely level. Inclination of the body of the microscope is permitted by a joint in the upright, which joint may be fastened in the larger stands by a set-screw operated by a lever. Stands Ia and IIb are also made with the English foot. Abundant space is left under the stage for the various attachments of the sub-stage.
2. The stage of Stands A, I, Ia and II is round, revolving and centering. The centering arrangement consists of two small thumb-screws so situated at the sides of the stage as to control motion of the stage in all directions, thus to a limited extent serving the purpose of a mechanical stage.