A London encyclopaedia, or universal dictionary of science, art, literature and practical mechanics : comprising a popular view of the present state of knowledge : illustrated by numerous engravings, a general atlas, and appropriate diagrams (1829)
Curtis, Thomas, fl. 1820 · London : Thomas Tegg · leaf 267
r sphericallyrounded. B is a double convex, and has bothsides spherically rounded. When these sides areunequally curved, as at C, it is termed a crossedlens. D is a plano-concave, having one sidespherically hollow. E is a double concave withboth sides hollow. F is a meniscus (so calledfrom its moon… … ing upon the plano-convex lens A D B, and pass-ing through it, are but half as much refracted asthey would be in passing through the doubleconvex lines A D B E, and therefore their focusor point of meeting is not at C but at F, whichis at twice the distance, or double the radius ofthe convexity of…
Encyclopedias and dictionaries · Aeronautics
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
