Page:Principles of Microscope.djvu/28

xxii Fig. C. A composite photograph of Fig. A and Fig. B.

This represents the combined contribution of the microscope and the observer's eye to the obfuscation and diffraction which mar the highly magnified microscopic image.

Fig. D. Group of typhoid bacilli imaged by Gordon's tandem microscope employed with the ground glass screen at rest. We have here the highly magnified microscopic image relieved from the blemishes (seen in C) which are referable to obfuscation and diffraction, but marred by the superimposed magnified image of the grain of the screen (vide pp. 236-237).

Fig. E. Group of typhoid bacilli imaged by Gordon's tandem microscope employed with the ground glass screen in motion. The highly magnified microscopic image has here been relieved both from the blemishes contributed by obfuscation and diffraction and from the superadded blemishes referable to the superimposition upon the picture of the magnified image of the grain of the screen.