c. The accuracy of the microphotometer tracings is in general

satisfactory. Tracings showing abnormal deflections from “darkness” to “clear film” are not susceptible of correction, and are omitted in deriving results.

d. The measures upon the tracings are also of satisfactory accuracy.

8. The differences in intensity between the continuous background and various points along the line contour are tabulated for the eleven stars under discussion.

9. The general results for the intensities at the centers of lines show an interesting relation to absolute brightness; the brighter stars have, in general, lines that cut more deeply into the background. A result of considerable interest is that the average residual intensity in the strong wide absorption lines is more than 30 per cent of the background intensity.