Corrugated translucent sheets and means securing the same

Claim 1

IN A ROOF, AN ASSEMBLY OF ROOFING ELEMENTS COMPRISING IN COMBINATION TWO RECTANGULAR CORRUGATED SHEETS DISPOSED SIDE-BY-SIDE IN A COMMON PLANE WITH THEIR ADJACENT LONGITUDINAL MARGINAL PORTIONS BENT PERPENDICULARLY TO THE GENERAL PLANE OF THE SHEETS AND PLACED TOGETHER IN SURFACE CONTACT, AT LEAST ONE OF SAID MARGINAL PORTIONS BEING OF U-SHAPED CROSS-SECTION AND HAVING HOOKED ENGAGEMENT WITH THE ADJACENT MARGINAL PORTION OF THE OTHER SHEET, THE REMAINDER OF THE TWO SHEETS PRESENTING TOGETHER A UNIFORMLY CORRUGATED SURFACE, A THIRD CORRUGATED SHEET PARTIALLY OVERLAPPING ONE TRANSVERSE MARGINAL PORTION OF EACH OF THE OTHER TWO SHEETS, THE AFORESAID LONGITUDINAL MARGINAL PORTIONS OF WHICH ARE CUT AWAY WHERE SAID THIRD SHEET OVERLAPS SAID OTHER TWO SHEETS, AND A JOINT-COVERING ELEMENT HAVING A BASE PORTION SHAPED TO CONFORM TO THE CORRUGATED FORM OF THE SHEETS AND OVERLYING SAID CUTAWAY PORTIONS AND UNDERLYING SAID THIRD SHEET WHERE SAID THIRD SHEET OVERLAPS THE JUNCTION OF THE OTHER TWO SHEETS, AND ALSO HAVING A HOOD-SHAPED PORTION EXTENDING OVER THE ADJACENT PARTS OF THE CONTIGUOUS LONGITUDINAL MARGINAL PORTIONS WHICH ARE IN HOOKED ENGAGEMENT AS AFORESAID, SAID HOOD-SHAPED PORTION BEING CLOSED AT ITS END ADJACENT SAID BASE PORTION.