All "Luxfer" Sidewalk Prisms, as illustrated, are installed in "The Luxfer Wrought Steel Interlocking Frames." This frame is made of cultivator bars 7/16 inch thick and 1½ inches high running at right angles with building, and channel bars 1 × 3/8 inches running parallel with building. The cultivator bars are punched with holes to admit channel bars. When the frame is assembled each joint is punched by a special machine to tighten and strengthen the frame. The frame when finished is the best frame obtainable for installing sidewalk Prisms and will stand a test of 400 lbs. to the square foot without any deflection whatever. These frames can be fitted with angles or weather strip on side next the building when desired.

NO IRON EXPOSED—Surface is all glass and concrete.—This frame has displaced altogether the old style cast-iron frames, as all danger of leaks through cracked or warped frames is eliminated.

Coal holes or hatches can be introduced where desired.

We galvanize frames, if necessary, for a slight additional charge.