To cook sea bass: Place top oven rack 4 inches from heat source.
Place an oven rack six inches below the heat.
Set an oven rack in the upper middle position.
Put the potatoes on the oven rack and bake until very tender, about 1 hour.
Place the top oven rack about 8 inches from the flame.
In a pinch, a cold oven rack can be used to cool a large batch.
Position the oven rack so the salmon is no farther than four inches from source of heat.
Adjust oven rack to top, bottom or center, as the recipe indicates.
Place an oven rack in the center of the oven.
Position the oven rack so the salmon will be two to three inches from the source of heat.