Abstract:
Spectra of the H-alpha line obtained with high dispersion and high spatial resolution are used to study some of the characteristics of chromospheric mottling on the solar disk. The fluctuations in intensity, indicated by the r.m.s. values, are given for delta lamda = 0.6 A., plus or minus 0.4A., plus or minus 0.2 A. as well as the line centre. The fine mottles have sizes less than 1800 km. Values of the total number of mottles visible on the disk are estimated from mottle counts made at slit positions on the solar disk at mu = 1.00 and mu = 0.45
