We roped up; I led with pro and the others followed up the "Chimney Variation" slot (5.4) right above the notch and another half pitch along the crest. We didn't like the looks of the start of the "Clyde Variation" with the snow. At 3 pm we could see that we would not be able to make the 200 additional yards along the crest to the summit and back in time. There was too much snow around on the blocks that would have to be maneuvered around with rope and protection necessary. There was a surprising amount of snow (but probably climbable upwards) on the southwest face even though it faces the afternooon sun. So we bailed and rappelled down, including some rappels in the U-notch; good sling anchors on the rock there too. Did not see any indication that others had tried the traverse to the summit. We did see people all over the glacier below. Others sucessfuly summited Sill via the Swiss Arete, and Thunderbolt via the right Underhill Couloir. One party was coming down the V- notch late; we didn't know if they went all the up the ice we could see there. The other three of us were Jan Lorenzen, R.J. Secor, and Maria ?.