Floating in different liquids

Obtain a tall, slender glass jar, test tube or bottle, and the following liquids: mercury, carbon tetrachloride, water and kerosene. You will also require a small iron or steel ball such as a ball bearing, or iron nut or bolt; a small piece of ebony or some other wood that sinks in water; a piece of paraffin wax; and a piece of cork. First pour some mercury into the glass jar, then some carbon tetra- chloride, some water and some kerosene.