Handbook: 280 of 287
LUXFER PRISM GLOSSARY.
Beam, Head beam. The beam supporting
the pavement at the "building line," commonly an I beam placed under
the inner edge of the pavement. See page 93.|
Canopies. External prism-plates in
separate frames set at an angle to the vertical. Usually this angle
is about 50°.
Day-light. The light of day. This
comes principally directly from the sky, and a small amount indirectly
from buildings, and substantially all of this comes primarily from
Depth. The depth of a prism plate is
the distance from its top to its bottom, measured along the vertical
edge of the prism plate.
Diagonal Canopy Lenses. Prism lenses
with tilted prisms placed in the sides of a canopy plate throwing
the light diagonally through the window.
Diffusion. When light falls upon some
unpolished bodies instead of being thrown off in one general
direction, it is thrown off in all directions. This action is called
diffusion. Almost all bodies have this property to a greater or
less degree. Walls which are not glossy have this property to a very
Electro-glazing. The process of
glazing pieces of glass into large plates by means of electrolysis.
See page 12.
Forilux. Plural, Foriluxes. A prism
plate set in a separate frame, and placed in a window opening,
substantially flush with the face of the building. See
Head Beam. The beam supporting the
pavement at the building line, commonly an I beam placed under the
inner edge of the pavement. See page 93.
Holland Shade. The particular glass
of goods used in shades over Luxfer Prism plates.
Illumination is the quantity of light
falling on unit surface. The illumination in a room is good, if
objects are easily distinguished therein. Hence intensity of
illumination varies as objects are more or less easily distinguished.
Iridian. Prism lenses having upon the
receiving face a design wrought in the material.