Lockyer, Norman, Sir, 1836-1920 · London : Macmillan and Co. · leaf 248
s, we know, is a round piece of glass,generally thickest in the middle, and we may look uponit as composed of an infinite number of prisms. Fig. 45shows a section of such a lens, which section, of course. TIGHT. :i3 n;,iy be taken in any direction through its centre, anda Httlc thought will show… … Fig. 45.—Action of a Convex Lens upon a beam of parallel rays. tliat when held at a certain distance from the lens a holewill be burned through it; this distance marks the focaldistance of the lens. If we place an arrow, ab, in front ofthe lens ;;/;/. v/e shall have an image of an arrow behind at
Astronomy · Solar system
Internet Archive · OCAD University Library · Public Domain Mark 1.0. Free to use for anything.
