Architectural screen and building unit therefor

Claim 1

AN ARCHITECTURAL SCREEN BUILDING UNIT COMPRISING: A PAIR OF IDENTICAL LONGITUDINALLY EXTENDED SIDE WALLS EXTENDING IN PARALLEL RELATION TO ONE ANOTHER AND HAVING COMPLEMENTAL INTERLOCKING MEANS CO-ENGAGEABLE WITH A SIMILAR UNIT WHEN DISPOSED IN OPPOSED FACE-TO-FACE RELATION THERETO; WEB MEANS BRIDGING SAID SIDE WALLS; SAID INTERLOCKING MEANS INCLUDING LOCKING LUGS DISPOSED IN SPACE RELATION ALONG THE CORRESPONDING EDGES OF EACH OF SAID SIDE WALLS; AND RECESSES DISPOSED ALONG THE OPPOSITE CORRESPONDING EDGES OF SAID SIDE WALLS FROM SAID LUGS FOR THE RECEPTION OF SAID LUGS WHEN A PAIR OF SAID UNITS ARE CO-ENGAGED IN OPPOSED FACE-TO-FACE RELATION; THERE BEING AN EQUAL NUMBER OF LUGS AND RECESSES ON SAID SIDE WALLS CORRESPONDINGLY SPACED AT OPPOSITE SIDES OF A TRANSVERSE MEDIAN LINE EXTENDING ACROSS SAID SIDE WALLS WHEREBY SAID UNITS ARE ENGAGEABLE WITH ONE ANOTHER IN LONGITUDINALLY STAGGERED RELATION ONE-HALF THE LENGTH OF SAID UNITS.