photopolarimeter (foto polarimeter)

[ photo-proce (fō'tō-proses), n. [« Gr. φῶς (φωτ-), light, + E. proce .] Any proce or method by which is produced, by the agency of photography, a matrix in relief or in intaglio from which prints can be made in ink; especially, the photographic production of relief plates from which impre ions are struck off in an ordinary printing-pre . It thus includes photogravure, but is especially applicable to such proce es of photo-engraving as photolithography and photo zincography. The chief kinds of photo-proce are differ entiated as follows. Heliotype is the production of a matrix in gelatin, from which printing is done directly in a lithographic pre , Photogravure is the production of incised or intaglio plates in metal. Photo-engraving is (properly) the production of relief-plates of any kind suited for printing, together with type, in an ordinary printing-pre ; though the term is often used to include photogravure also. Photo-engraving is particularly applicable to the reproduction of pen-drawings; when used for pictures, such as ordinary photographs, it is nece ary, 4456 a molding or cutting-tool, so that, as the longer arm traces every figure on the screen, the shorter one reproduces it in the clay. photosphere (fōtō-sfēr), n. [ = F.photosphère, luminous envelop, supposed to consist of incandescent matter, surrounding the sun. According to Kirchhoff, the sun's photosphere is either solid or liquid, and is surrounded by an extensive atmosphere, composed of gases and vapors of the substances incandescent in the photosphere. According to the view now more generally accepted, the photosphere is a shell of luminous cloud that is, the solid or liquid particles which produce the light are minute, and di eminated through the lower strata of the solar atmosphere. photospheric (fō-to-sfer'ik), a. [ Phragmites tric current as produced or varied in intensity by the action of light, as when the electrical resistance of selenium is altered by light. photoxylography (foto-zi-log'ra-fi), n. [ ce of producing an impre ion of an object on wood by photography and subsequent proce es, and then printing from the block.