sentences:  Both the pick and the shovel were later silver plated and preserved as mementos in the office of the Mayor.Following significant progress in construction a cornerstone laying ceremony was planned to coincide with the celebration of Pittsburgh's Centennial.On March 26, 1916 the celebration of the 100th anniversary of incorporation was held in Pittsburgh and a parade wound through downtown Pittsburgh ending at a steel-framework of what would become the new City-Council Building.Three cornerstones were laid during the celebration, including one for the City, one for the County, and one for the workers, each of which contained time capsules.