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The fine structure of nonspot prominences are studied from Ha filtergrams. The size of the smaIlest prominence structures increases with height above the chromosphere. Some prominences contain structures close to 89 arc second, which is the spatial resolution in the present data. The effective thickness of many nonspot prominences ranges between 4 • 107 cm and 1.5 x 108 cm. An apparent downward directed motion is observed in the majority of the prominences. No preferred direction of the motion is seen in regions composed of comparatively large diffuse structures. Some bright threads are visible for 1 hr and longer. Bright knots have an average observed lifetime of about 8 min. The process of condensation and subsequent destruction of prominence fine structure appears to take place on a very short time scale compared to the life time of the regions where prominences may exist. The observed Ha brightness of the prominences in the present data may be accounted for as scattered chromospheric radiation.

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High spatial resolution spectral observations of five hedgerow prominences were made in Ha, He I D3 and Ca Ix H and K.The observed relations between the lines were not the same in all prominences. The Ca II H and K lines were 2-4 times brighter relative to Ha and D3 than predicted theoretically. The optical thickness of Ha was less than for the H and K lines, the Ha was optically thin in medium faint prominence structures. Faint structures appeared slightly hotter than bright structures.