The radar reflectivity of thunderstorms at 10 cm is shown to be a good indicator of hail and a rough measure of its size. The physical characteristics of the hailstorm, as deduced from 3- and 10-cm echoes of a large number of New England hailstorms of 1961, are described. It is shown that the hailstorm possesses no great singularity beyond that of its significantly high reflectivity. It is concluded that the larger hail-stones contribute little to the total liquid water content of the thunderstorm as the highest reflectivities measured are easily accounted for by low concentrations of large hail, wet or dry.