Over three decades ago - too cheap to take the tram or train - Mark and I walked down the entire length of the glacier into Bar Nationale in Chamonix, after having done our first route together (the classic traverse of the Geant and Rochefort). During the descent on the Mer de Glace I caught Mark before he tumbled into a crevasse on this first outing together. (Of course he returned the favor and hour later, when my first generation Chouinard rigid crampons broke and I took a spill.)