Spectroheliographic Observations

In this paper we describe the scans of solar images by the use of the solar spectrograph of the Purple Mountain Observatory, attached with an apparatus which makes the solar image and photographic plate move synchronously. In front of the plate-holder there is a slit, of which the width can be adjusted. By rotating the grating we can scan solar monochromatic images in the continuum and in the spectral lines H₂(λ6563Å), H_δ (λ4202Å), D₂(λ5890Å), Ca Ⅱ K (λ3934Å), D₃(λ5876Å) and FeI(λ6302Å). It may be seen from the photographs that monochromatic images in various spectral lines exhibit evident differences.