The outlines of physics: an elementary text-book . werof which is slight, the violet light will be brought to afocus at V and red light at r. By placing behind this adiverging lens of flint glass (^F, Fig. 373), which is muchmore highly dispersive, the violet rays, which tend to a 400 THE OUTLINES OF PHYSICS focus too soon, will be bent outward more strongly thanwill the red, and it is possible to construct these lenses sothat both sets of rays will come to a common focus at vr (Fig. 374). Such a com-bination is called an aehro-matie lens. Achromaticlenses are always used inthe objectives of t
The outlines of physics: an elementary text-book . werof which is slight, the violet light will be brought to afocus at V and red light at r. By placing behind this adiverging lens of flint glass (^F, Fig. 373), which is muchmore highly dispersive, the violet rays, which tend to a 400 THE OUTLINES OF PHYSICS focus too soon, will be bent outward more strongly thanwill the red, and it is possible to construct these lenses sothat both sets of rays will come to a common focus at vr (Fig. 374). Such a com-bination is called an aehro-matie lens. Achromaticlenses are always used inthe objectives of telescopes,microscopes, and other opti-cal instruments where chro-matic aberration would bedetrimental. 368. The Microscope. — The essential parts of thisinstrument, namely, the ob-jective and the eyepiece, are the same as in the tele-scope; but the objective is modified to adapt it to thework for which the microscope is intended. This consistsin producing an enlarged real image of a small objectnear at hand, and further magnifying this image by. Pig. 373.
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishe, booksubjectphysics
