Any person engaged in or employing others in excavating, or otherwise in any manner obstructing, a portion or all of any street, sidewalk, alley or other public way at all times during the night shall install and maintain at least two illuminated red lamps, which shall be securely and conspicuously posted on, at or near each end of the obstruction or excavation, and if the space involved exceeds 50 feet in extent, at least one additional lamp for each added 50 feet, or portion thereof, excavated or obstructed.
Penalty, see § 10.99