A golf ball having improved driving characteristics includes a hard, hollow sphere
surrounded by an outer. A second layer may be disposed between the sphere and the
outer cover. The hollow sphere is made from a hard material such as a metal, metal
alloy, or intermetallic material and may be solid, perforated or porous. The second
layer surrounding the sphere is generally made of a natural rubber or synthetic
polymer or a combination of each which is surrounded by an outer cover made of
an ionomer, urethane or balata. The hard sphere preferably contains a gas. A golf
ball of this construction has improved performance characteristics such as low
spin rate and further distance.