1. IN A CONCRETE FORM FOR USE, IN THE CONSTRUCTION OF A BRIDGE OVERHANG, IN CONJUNCTION WITH AN OUTSIDE BRIDGE I BEAM, A PLURALITY OF BRACKETS SPACED LENGTHWISE OF SAID BEAM, EACH BRACKET INCLUDING A SUPPORT AND MEANS AT ONE END OF SAID SUPPORT CONNECTED TO THE WEB OF SAID BEAM AND EXTENDING APPROXIMATELY AT RIGHT ANGLES THERETO WITH ITS SUPPORTING SURFACE SPACED BELOW THE OUTER TOP FLANGE OF SAID I BEAM, AND UPWARDLY DISPOSED KEEPERS, ONE LOCATED ON EACH SIDE OF SAID SUPPORT, A PLURALITY OF SILLS, ONE FOR EACH SUPPORT AND EXTENDING LENGTHWISE THEREOF BETWEEN THE KEEPERS, THE HEIGHT OF EACH SILL BEING GREATER THAN THE HEIGHT OF SAID KEEPERS, A PLURALITY OF SPACED PARALLEL JOISTS, EACH SUPPORTED BY A PLURALITY OF SILLS AND DISPOSED AT RIGHT ANGLES THERETO, AND A FLOOR SUPPORTED BY SAID JOISTS WITH A MARGIN IN CONTACT WITH THE UNDERSURFACE OF THE OUTER TOP FLANGE OF SAID BEAM, EACH OF SAID MEANS INCLUDING BOLTS EXTENDING THROUGH SAID WEB AND LOCATED ADJACENT TO THE SILL-SUPPORTING SURFACE OF ITS SUPPORT AND EXPOSED ON OPPOSITE SIDES THEREOF, AND A SERIES OF VERTICALLY ADJUSTABLE MEANS CARRIED BY EACH SUPPORT AND SPACED LENGTHWISE THEREOF IN ENGAGEMENT WITH THE UNDERSURFACE OF THE SILL FOR THAT BRACKET.