. Beck microscopes. Microscopes. Beck-Chapman Opaque Illuminator. This illuminator was originally devised by Messrs. Chapman & Aldridge, and has been modified and sold under various trade names. A modification (patent applied for) is here introduced which simplifies the apparatus without injuring its utility. With the Beck aplanatic ring illuminator, the size of the object that can be examined is limited to about f in., whereas with the Beck-Chapman illuminator, the size of the object is immaterial. The construction of this apparatus is shown in Fig. G. The light from a small electric bulb
. Beck microscopes. Microscopes. Beck-Chapman Opaque Illuminator. This illuminator was originally devised by Messrs. Chapman & Aldridge, and has been modified and sold under various trade names. A modification (patent applied for) is here introduced which simplifies the apparatus without injuring its utility. With the Beck aplanatic ring illuminator, the size of the object that can be examined is limited to about f in., whereas with the Beck-Chapman illuminator, the size of the object is immaterial. The construction of this apparatus is shown in Fig. G. The light from a small electric bulb (A) is thrown from the side into the microscope, through a condensing lens (B), upon a mirror (C) placed above the object glass (D). The mirror has an aperture in the centre. The mir- ror throws an annular ring of light, upon metal reflectors (E, E' and E"), which surround the object glass and concentrate the light upon the focal plane of the object glass giV'ing a brilliant illumination upon any object or surface being examined. The light falls upon the object in the form of a hollow cone, so that no direct light enters the microscope and the object is rendered visible by reflected light. To avoid the necessity of adjusting the height of an independant lamp when objects of a different thick- ness are being examined, a self-contained source of light is provided, consisting of a 6 volt lamp with condensing lens, in a well ventilated lamp-house, giving the necessary adjustments for the lamp. This lamp may be used with batteries or accumulators, or with suitable resistance or transformer from the mains. The mount of the illumin- ator, with its angular mirror, lamp-house and condenser, screws into the microscope by means of a revolving fitting (G). Its lower portion has a dovetailed slide (H) into which the various object glasses, with their reflectors are fitted. The illuminator is made with H in. (32 m/m.), fin. (16 m/m.), | in. (8 m/m.) and ^ in. (4 m/m.) object glasses. T
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Keywords: ., bookcontributorgerstei, bookleafnumber90, booksubjectmicroscopes
