Several weeks ago, I had the privilege of participating in a tour of Grand Central Terminal with Francis Marrone, the noted New York architectural historian. After perhaps a thousand trips in and out of the terminal wearing blinders, he pointed out the richness of details, large and small, and the remarkable and enduring mystery and myth of the building that transformed New York in 1913.The impact of this landmark architectural treasure was by no means certain when it opened  since train travel was in its infancy nor were the changes created by the renovation anticipated.  It has become a hub for the comings and goings of about 750,000 people a day.