A Hand-book of OpticsBlanchard and Lea, 1858 - 279 pages |
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Common terms and phrases
already explained angle of incidence angle of refraction apparent magnitude centre circular coincide colour consequently convergent lens convergent power convex crystal crystalline curves dark diameter diminished direction disk distance distant objects distinct diverging double refraction effect equal extreme focal length foci focus of incident formed glass greater homogeneous light humour illuminated inches incident rays index of refraction intensity lenses less luminous point magnifying power manner microscope motion moved object-glass observer opaque optical axis parallel rays pencil of rays pencils proceeding perception perpendicular phenomena picture plane of polarization plate position principal focus principle prism produced proportion radius rays proceeding reflected rays refracting power refrangibility rendered represented in fig retina right angles screen seen sine solar light space spectrum spherical spherical aberration spherical reflector suppose surface telescope tion tourmaline transmitted tube violet visible object vision visual angle vitreous humour yellow
Popular passages
Page 707 - When a ray of light passes from one medium to another, it is refracted so that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the velocities in the two media.
Page 534 - R" c, passing from glass or water into air, are bent in the directions c I, c i', c i" from the perpendicular c o. 98. This result, being too hastily generalised, is sometimes announced as follows : — When a ray of light passes from a rarer into a denser medium, it is bent towards the perpendicular, and from a denser into a rarer from the perpendicular, which is by no means generally true. Such...
Page 743 - A plane mirror, moveable about an axis in its own plane parallel to the axis of the Earth, revolves from east to west with half the Sun's apparent diurnal motion.
Page 617 - ... distance, the image produced by objects at great distances will become indistinct; and that, on the other hand, when the eye so accommodates itself as to render the image produced on the retina by distant objects distinct, the image produced by an object at twelve inches distance will become indistinct.
Page 580 - Rule 2, if the side whose radius is 2 is turned to parallel rays. 5. The lens which has the least spherical aberration is a double convex one, whose radii are as 1 to 6. When the face whose radius is 1 is turned towards parallel rays, the aberration is only...