Читать книгу Essays on the Microscope - George Comp Adams - Страница 37

As in the former one, place the slider-holder K, with a slider of objects in it, in the stage N I S; move the arm C D, in its socket, so that a mark on the side is brought to the edge of the socket; then turn the arm till the magnifier is directly central over the object; look down the tube A B, and during that time, reflect the light strongly and clearly up into it from the mirror O below; and then, while you are looking through the body, gently turn the pinion at M to the right or left, till you see the object magnified in the most distinct and well-defined manner. Attending properly to this mode is the only care necessary to use any microscope whatsoever; and for want of doing which, many a beginner finds a difficulty in using properly his instrument. For price, see the list at the end.

For opake objects, you take away the slider-holder, K; place on the stage either the concave glass, s, or the nippers, b; screw the concave speculum, e, to the arm, a, which place on the stage with the arm in the hole, I. The light is now to be reflected into this concave dish from one of the mirrors, O, below, and it will thus be strongly condensed upon the object. With this concave speculum any of the magnifiers in the wheel, P, may be used. When the single silver concave, f, is used, it is screwed to the arm C D, and the one, e, and arm, a, are not then applied.

For further directions for the management of microscopes, the light, &c. see Chap. IV. p. 129, and sequel.