![]() ![]() It is formed either by putting a convex lens at its lower end or, in better makes, by putting a convex and concave lens together in the same position. The objective is a small tube containing a combination of lenses. By rotating the nose plate the desired objective could be brought in line of light rays. On the lower convex side of nose plate are present 2, 3, or 4 rounded holes tor attachment of objectives of different powers. The nose piece or nose plate is attached with the body in such a way that it can easily rotate on its axis or point of attachment. The nose piece is a concavo-convex circular disc attached to the lower end of body tube. The most commonly usable eye pieces are of the magnifications 5× 10× and 15× (Fig. It is a compound lens made up of a lower convex lens and an upper plain lens. ![]() With the upper end of body tube is attached a narrow and smaller tube which houses the eye piece. The clockwise movement of coarse adjustment knob brings the body tube downwards and its anticlockwise movement takes the body tube upwards. This knob is used for more accurate focusing while using the instrument for high magnifications. A little below the coarse adjustment is present another comparatively smaller knob-the fine adjustment knob, either on the upper or lower end of curved inclinable limb. ![]() The movement of the body tube is required for purpose of focusing. ![]() It can be moved up or down on the curved limb through a knob the coarse adjustment knob. The body tube, in almost all types of compound microscopes, is about 160 mm. The body tube is a hollow cylindrical metallic tube attached to the upper end of curved inclinable limb through a rack and pinion mechanism. Usually, the curved limb or body should not be tilted unless unavoidable because, in doing so the centre of gravity of the apparatus is disturbed and there are enough chances of it’s falling down. Just above the foot, near its joint with curved limb of body is present an inclination joint on which the curved limb or whole of the microscope could easily be tilted according to whether the observer is in sitting position or in standing posture. The foot is generally heavy in order to increase the centre of gravity of the whole instrument. 2) which rests on table top or any other surface on which the microscope in kept. The foot is generally horse shoe-shaped structure (Fig. The stand is made up of a heavy foot which carries a curved inclinable limb or arm bearing the body tube. The below mentioned article provides a labelled diagram of compound microscope. ![]()
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