Receiving Face. The face of the prism
lens that is ordinarily set to the weather.|
Reflection. When light falls upon a
body, a part of it is thrown off. This action is called reflection.
Refraction. When light passes from one
medium into another, such as from air to glass, it undergoes a change
of direction. This action is called refraction.
Reveal. Any outward projection over and
at the sides of a window measured from the plane of the window.
Shade-- See window shade.
Sky. The atmosphere contains dust,
water particles, vapor, etc., which form a diffusing screen rendered
bright during the day by the light of the sun and constituting the
Slope. The angle at which a canopy
sets, measured from the vertical.
Tilted. A prism lens whose prisms do
not run parallel to the top or bottom of the lens, but make an angle
thereto, is said to have its prisms tilted.
Vault. The space under a pavement or
sidewalk separated from the basement by the lucidux.
Window Shade is a roll of cloth or
paper capable of being conveniently extended over an opening to shut
out an abnormal amount of light. See page 100.
Zenith. The point immediately overhead.
Zenith Distance. The angle from the
zenith to the line of the direction of the lowest light coming over
the building opposite.
Zenith-tangent. The street width
divided by the height of the opposite building. Tangent of zenith
distance. See page 80.