  Standard Monte Carlo simulations have been performed on improved lattices to
measure the wave functions and sizes of the scalar and tensor glueballs at four
lattice spacings in the range $a= 0.05 - 0.145$ fm. Systematic errors from
discretization and finite volume are studied. Our results in the continuum
limit show that the size of the tensor state is approximately two times as
large as that of the scalar glueball.
