A text book of physics, for the use of students of science and engineering (1918)
Duncan, John, d. 1941, Starling, Sydney George, 1873- · London Macmillan · leaf 588
Fig. 509. Caustic by reflection at sphericalsurface. PARABOLIC MIRROR 563 Parabolic mirror.—A spherical mirror does not bring a beam toa point focus unless it is confined to a small area. In the event ofit being desired to bring a large beam to a point focus, it is necessaryto use a parabolic… … Fig. 510.—Reflection by parabolic mirror. The whole mirror is produced bya revolution of the diagram aboutPA as axis. The chief propertyof a parabola is that a line FBthrough the focus, and a line BSparallel to the axis, make equalangles with the tangent CBD ofthe parabola, and also with thenormal…
Physics
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
