Sec. 9. Requirements as to materials and specifications
generally.
It shall be unlawful for any person to erect or maintain any
electric sign except as prescribed in this article, and to be permitted
under this article, an electric sign must be composed entirely
of metal, or other suitable material, excepting the lettering
or advertising designs to be illuminated, which shall be composed
of glass or other transparent or semi-transparent substance of
sufficient thickness to be reasonably safe from easy breakage, and
where the electric lights illuminating said sign are concealed,
there shall be at least one electric light for each letter or device
on said sign and not less than ten lights in any sign. (Id.)
