…a solid geometric figure whose two ends are similar, equal, and parallel rectilinear figures, and whose sides are parallelograms…
…a device for producing plane-polarized light, consisting of two pieces of optically clear calcite or Iceland spar cemented together with Canada balsam in the shape of a prism…
…a reflecting prism in which the light is reflected on two 45° surfaces and returned parallel to the incoming beam…
…a reflecting prism in which the reflecting surface is in two parts that are angled like the two sides of a pitched roof…
…a mass of sedimentary material scraped off a region of oceanic crust during subduction and piled up at the edge of a continental crustal plate…
…a pair of binoculars using two Porro prisms at right angles, resulting in a conventional instrument with objective lenses that are further apart than the eyepieces…
…a pair of binoculars using two roof prisms, resulting in an instrument with parallel sides and objective lenses that are the same distance apart as the eyepieces…
