. How to use the microscope; a guide for the novice. Microscopes. 38 HOW TO USE THE MICROSCOPE under-stage collar until the outside surface of the top lens is flush with the surface of the stage and in touch with the under side of the object. The lamp is placed 4 or 5 inches from the mirror, the flam side of which is used, and light is directed through the condenser. Then the object is focussed with the objective in the usual way. With the iris diaphragm nearly closed, the condenser is gradually moved downwards in the under-stage collar until the flame of the lamp is imaged in the field as a c
. How to use the microscope; a guide for the novice. Microscopes. 38 HOW TO USE THE MICROSCOPE under-stage collar until the outside surface of the top lens is flush with the surface of the stage and in touch with the under side of the object. The lamp is placed 4 or 5 inches from the mirror, the flam side of which is used, and light is directed through the condenser. Then the object is focussed with the objective in the usual way. With the iris diaphragm nearly closed, the condenser is gradually moved downwards in the under-stage collar until the flame of the lamp is imaged in the field as a central streak of light between dark margins. The dia-. FiG. —Abbe Condenser Mounted for Under-Stagb. phragm is finally adjusted to the most suitable aper- ture. The edge of the flame is turned towards the mirror. With the condenser thus used, the centre of the field is critically and brightly illuminated, enabling the worker to get the best possible results with medium and high-power objectives, which invariably give their best definition at one point of the field only, and it is that point, in the centre, upon which light is concentrated. If it is desired to light the whole field, the flat of the flame may be turned to the mirror, or rays from the flame can be parallelized. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Hall, Charles Albert, 1872-. London, A. and C. Black
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Keywords: ., bookcentury1900, bookdecade, booksubjectmicroscopes, bookyear1912
