Timecapsule: February 19, 1921

On this date the cornerstone for San Francisco's spectacular Palace of the Legion of Honor Museum was levered into place.

The Museum was to be a vehicle for the cultural pretensions of the notorious Alma Spreckels. This social-climbing dynamo envisioned her Museum as a far western outpost of French art and culture. Drawing on the vast fortune of her husband -- sugar baron Adolph Spreckels -- she constructed a replica of the Parisian Palais de Legion D'Honneur out at Lands End. Alma would stock the place with art treasures from her own vast collection -- including one of the finest assemblages of Rodin sculpture on the planet.

You've probably heard plenty on the subject of Alma Spreckels' rags-to-riches clamber up the social slopes of Pacific Heights, but what's really interesting us today is not what's inside her museum, but what lay underneath that cornerstone in 1921.