The Fine Structure of the Solar Chromosphere.

The solar limb has been studied visually and photographically in the light of H alpha and the combined results are reported. The appearance of a spicule changes with wavelength settings. Effects due to changes of spicule velocities with height and opacity-wavelength relations are indicated. A number of bright spicules seen in the wings are identified with bright mottles seen in the line core. The dark band appears between delta lambda plus or minus 1.0 A and delta lambda plus or minus 0.70 A. Examination of a small mottle cluster in a series of photographs taken in steps from H alpha 0.85 A to H alpha 0.10 A leads to a three-dimensional model of a typical mottle cluster. Author