. How to use the microscope; a guide for the novice. Microscopes. THE SIMPLE MICROSCOPE 5 sometimes useful, as it can be held to the eye while the hands are left free to manipulate the object. The Coddington lens used to be held in high esteem ; it is a thick, double-convex glass grooved about the middle, the groove being blackened and acting as a diaphragm. It gives fair magnifying power, but has some imperfections ; thus, it does not yield a sufficiently large and flat field, and the working distance between lens and object is too short. It has to be remembered that working distance lessens
. How to use the microscope; a guide for the novice. Microscopes. THE SIMPLE MICROSCOPE 5 sometimes useful, as it can be held to the eye while the hands are left free to manipulate the object. The Coddington lens used to be held in high esteem ; it is a thick, double-convex glass grooved about the middle, the groove being blackened and acting as a diaphragm. It gives fair magnifying power, but has some imperfections ; thus, it does not yield a sufficiently large and flat field, and the working distance between lens and object is too short. It has to be remembered that working distance lessens with increase of power, and that the shorter this. Fig. 2.—Aplanatic Magnifier, showing Arrangement OF Lenses. distance is, the less is the size of field and the degree of illumination of the object. Lenses of the Cod- dington pattern cost from 4s. 6d. to about 9s. For splendid definition, size, and flatness of field, and good working distance, the Aplanatic or Platyscopic lenses are the best in the market. They consist of three lenses cemented together, and are to be had of different powers and ia various mountings to suit the purchaser's requirements. Mr. John Brown- ing, 146, Strand, London, supphes in pocket moimts with powers ranging from 10 to 30 diameters; Messrs. W. Watson and Sons, Ltd., 313, High Hol- born, , supply in three patterns of mounting,. 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
