As the aluminium is forming, a solidified bath layer, the so-called ledge, protects the cell sidewall from corrosive electrolyte and reduces the heat loss from the cell.
The general setting of each colony along with height of cliff, cliff aspect, height of occupied ledges, approximate ledge width, and distance to the sea, were described.
Colony 4 had 29 empty nests, all on accessible ledges: a depredated egg, fox scat, and bear scat full of feathers were found nearby.
They build nests on rock ledges or near the ground rather than in trees.
Unlike the experiment, the ledge has a greater amplitude for the simulation.
At 100 m, a thick sandstone ledge shows balland-pillow structures in the topmost part.
The elevation of the top of the ledge should therefore reflect the height of the water table.
Located on a rock ledge about 30 m above the beach, it was difficult to reach, but contained a small, black chick.
