Good progress is being made in the construction of the Mauch Chunk inter-boro bridge. Concreting of the floor and sides began today. It is proceeding rapidly and is expected to be finished before July 1, weather permitting. The big job lies ahead. That is the elevation of Routes 209 and 309 about five feet to the level of the new bridge. The dip that now exists is to be filled in. Iron posts and railing have arrived and will be installed after the concrete cures, which takes about seven days.