A theoretical analysis is developed about the elastic radiations by a wavesource in spherical shape, whose surface is partially released from internal pressure. The displacement is separated to P- and SV-pulses, each being represented in the forms of infinite series consisting of the Legendre polynomials, exponential and trigonometric functions. These expressions can be employed to explain the actual behavior of elastic radiations in small explosions, if the time-dependence of source pressure, p(t), is suitably selected. The initial rise of the displacement as well as the particle velocity for arbitrarily chosen p(t) are discussed and numerical results are calculated in case of p(t) equals sin**2 ( pi tau / tau //0) (0 less than equivalent to tau less than equivalent to tau //0). In the seismic model experiments, p(t) generally rises and vanishes with a smooth change as in this example.