CONVEX  See also:

• MIRROR (through O. Fr. mirour, mod. miroir, from a sup-posed Late Lat. miratorium, from mirari, to admire)

MIRROR Position of See also:

• OBJECT

Object . Position of See also:

• IMAGE (Lat. imago, perhaps from the same root as imitari, copy, imitate)

Image . See also:

• CHARACTER (Gr. xapareri7p, from xap&crew, to scratch)

Character of Image . to Between co and A A The above discussion of spherical mirrors assumes that the mirror has such a small See also:

• APERTURE (from Lat. aperire, to open)

aperture that the reflected rays from any point unite in a point . This, however, no longer holds when the mirror has a wide aperture, and in See also:

• GENERAL
• GENERAL (Lat. generalis, of or relating to a genus, kind or class)

general the reflected rays envelop a See also:

• CAUSTIC (Gr. rcavvraubs, burning)

caustic (q.v., see also See also:

• ABERRATION (Lat. ab, from or away, errare,, to wander)

ABERRATION) . The only mirror which can sharply reproduce an object-point as an image-point has for its See also:

• SECTION
• SECTION (Lat. sectio, cutting, secare, to cut)

section an See also:

• ELLIPSE (adapted from Gr. EXkei 'tc, a deficiency, iXXeirely, to fall behind)

ellipse, which is so placed that the object and image are at its foci . This follows from a See also:

• PROPERTY

property of the See also:

• CURVE (Lat. curvus, bent)

curve, viz. the sum of the See also:

• FOCAL

focal distances is See also:

• CONSTANT, BENJAMIN (1845-1902)

constant, and that the focal vectores are equally inclined to the normal at the point . More important than the elliptical mirror, however, is the parabolic, which has the property of converting rays parallel to,the See also:

• AXIS (Lat. for " axle ")

axis into a See also:

• PENCIL (Lat. penicillus, brush, literally little tail)

pencil through its See also:

• FOCUS (Latin for " hearth " or " fireplace ")

focus; or, inversely, rays from a source placed at the focus are converted into a parallel See also:

• BEAM
• BEAM (from the O. Eng. beam, cf. Ger. Baum, a tree, to which sense may be referred the use of " beam " as meaning the rood or crucifix, and the survival in certain names of trees, as horn-beam)

beam; hence the use of this mirror in See also:

• SEARCH, or VISIT AND SEARCH

search-See also:

• LIGHTS, CEREMONIAL USE OF

lights and similar devices .