"Dioptric" Quotes from Famous Books
 ... AAA represents in plan an ordinary Fresnel's dioptric fixed light apparatus, and BB' a hemispherical mirror (either metallic or dioptric on my father's principle) which is made to revolve with uniform speed about the burner. This mirror, it is obvious, intercepts the rays of one hemisphere, and, returning them through the flame (less loss by ...
— The Works of Robert Louis Stevenson - Swanston Edition Vol. XXII (of 25) • Robert Louis Stevenson |
