focimeter

[ Eng.focus, and Gr. metron =a measure.] Phot .. An instrument for a isting in focusing an object in or before a camera. This consists usually of a lens of small magnifying power. fō-cus, s. [Lat.=a fireplace, a hearth, a firepan, a brazier.] I. Ord . Lang .: Any place from which an influence concentrated form. ( Lit. & fig .) A. Intransitive : 1. To gather foam or froth; to froth; to be covered with froth or foam. "The river nobly foams and flows." Byron: Childe Harold, iii. 55. 2. To become filled with foam, as a steam-boiler. 3. To be violently agitated; to be in a rage or fury. "He foameth and gnasheth with his teeth."- Mark ix. 18. *B. Transitive : 1. To cause to foam; to make foamy or frothy. 2. To throw out with violence or rage. "Foaming out their own shame." -Jude 13. foam-ing, pr . par ., a . & 8. [FOAM, v.] A. & B. As pr. par . & particip . adj.: (See the "Her fancy followed him through foaming waves." Cowper : Task , i. 539. verb.) II. Technically . 1. Optics: A point at which the rays of light refracted from a convex lens, or reflected from a concave mirror, are most concentrated; a point in which such rays meet, or tend to meet, if produced either backward or forward. 2. Conic sections : IMG:content-1839.png:[blocks in formation] focusing-gla , s. Phot.: A gla used for magnifying the image on the ground gla in the camera, to enable the operator to get it into better focus.