Topological series of isolated plane curve singularities

A railing construction comprises a laterally disposed sub rail member which supports a top rail, and a support bracket at either end of the sub rail for securing the sub rail to a wall or post. The bracket includes a generally vertically disposed member which is provided with a bolt hole through the upper end thereof. A pair of generally parallel web members extend normally from the lower end of the vertical member, the lower web member extending farther outward and including an obliquely upwardly extending flange at the distal end thereof. The slot between the two web members is adapted to receive the sub rail therein only when the bracket is canted downwardly toward the sub rail. As a bolt passed through the bolt hole is tightened into a wall or post, the canted bracket approaches vertical, and the flange and the lower surface of the upper web lever the sub rail into rigid engagement.