 | Leonard Dunnell Gale - 1838 - 280 стор.
...focus of a concave mirror is the point in which the reflected rays meet. The centre of concavity is the centre of the sphere, of which the mirror forms a part. Parallel rays falling on a concave mirror are converged to a focus halfway between the centre of concavity,... | |
 | John Johnston - 1846 - 314 стор.
...the mirror is a part, and the surface of the mirror. Let AEB, figure 158 a, be a concave mirror ; C, the centre of the sphere of which the mirror forms a part ; and d efg h parallel rays. After reflection they will be collected in the focus, F, where the light... | |
 | John Johnston - 1854 - 420 стор.
...sphere of which the mirror is a part, and the surface of the mirror. Let AEB, be a concave mirror ; C, the centre of the sphere of which the mirror forms a part ; arid d efg h parallel rays. After reflection they will be collected in the focus, F, where the light... | |
 | Benjamin Silliman - 1859 - 750 стор.
...concave mirror, fig. 401, converge, after reflection, to a point equi-distant between the mirror and the centre of the sphere, of which the mirror forms a part. This point is called the principal focus. Rays of light emanating from the principal focus of a concave... | |
 | Benjamin Silliman - 1861 - 780 стор.
...concave mirror, fig. 327, converge, after reflection, to a point equidistant bctween the mirror and the centre of the sphere, of which the mirror forms a part. This point is called the principal focus. Rays of light emanating from the principal focus of a concave... | |
 | Adolphe Ganot, William Guy Peck - 1871 - 516 стор.
...curved surface. We shall consider the case in which the reflecting surface is a segment of a sphere. The following definitions apply equally to concave...through the axis is called a principal section. Thus, MN, Fig. 1 62, represents a principal section of a concave mirror, A is its vertex, C its optical centre,... | |
 | Thomas Ruggles Pynchon - 1873 - 644 стор.
...of a spherical mirror of this description. MN is the mirror, A is its middle point or centre, C is the centre of the sphere of which the mirror forms a part, and AB is a line perpendicular to the middle point of the mirror. Now upon the line AB — the principal... | |
 | Adolphe Ganot - 1881 - 550 стор.
...reflecting surface is a segment of a sphere. The following definitions apply equally to concave and eonvex mirrors: — The middle point of the mirror is called...sphere, of which the mirror forms a part, is called the centre of curvature. The indefinite straight line through the centre of curvature and the vertex is... | |
 | Royal Society (Great Britain) - 1882 - 434 стор.
...we call centering is accomplished by the three screws which attach the mirror to the cap, and causes the centre of the sphere of which the mirror forms a part to be at the centre of the object-glass. To test this point a tube 1 foot long is put on the collimator... | |
 | Condict Walker Cutler - 1889 - 364 стор.
...mirrors. Curved mirrors may be : Spheroidal. Parabolic. A. Spheroidal mirrors. The centre of curvature is the centre of the sphere of which the mirror forms a part. The princ ipal axis is the line drawn from the centre of curvature to the centre of the mirror. The... | |
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The following definitions apply equally to concave and convex mirrors : The middle point of the mirror is called its vertex. The centre of the sphere, of which the mirror forms a part, is called the optical centre. 
