Cheap and efficient, yes, but progress? I don't think so! Lehigh County in eastern Pennsylvania is replacing another one of the wonderful old stone bridges with whatever it is you wish to call the new one. The old bridge is a work of art able to be appreciated by anyone; one need not be a stonemason. The new bridge is able to be appreciated by engineers and accountants and metallurgists perhaps, but hardly an historic structure worthy of preserving. A nearby resident thinks the old one will be torn down rather than restored or saved as a walking bridge, and I will check on this when I return to the east. 
