Saw an aperture open in the rim, and that was enough.

This is particularly so at the southern end where an irregular gap exists in the rim.

The flag marked one of the dips in the rim at the far side.

They were standing in the outer rim, the customary spectators' position.

There is also a small gap in the western rim which protrudes to the west.

At once he went through the air lock, stood in the rim of its outer door and found himself fourteen feet above ground level.

This is most noticeable at the southern end where a gap exists in the rim.

Water began to spill into the basin through holes in the rim.

There is an outward protrusion in the rim to the south.

Diaphragms are also available with different types of springs in the rim.