The Number of Spicules in the Middle Chromosphere.

Statistics are given for the number of Ha spicules observed at the solar limb for heights of 3000 km and above. The observed numbers are analyzed to obtain the spatial distribution of spicules. It is found that at a height of 3000 km there are about 9.3 x 10 spicules on the sun and that these spicules cover about 0.6 per cent of the solar surface.