334 C. A. Young—Spectroscopic Notes. 
b’s, H, and other similar tests, with the instrument thus ar- 
ranged. The spectroscope is mounted upon a strong plank, 
stiffly braced, and this is attached by powerful ring-clamps to 
the tail-piece of the twenty-three-inch equatorial of the Halsted 
observatory, so that the image of the sun falls directly upon 
the slit. 
The detailed examination of the spot-spectra has been thus 
far confined mainly to a few limited regions in the neighbor- 
hood of C, D and d. 
_ With the high dispersive power employed, the widening and 
“winging” of the heavier lines of the spectrum is not well 
seen, not nearly so well as with a single prism spectroscope. 
to motion, no ‘“ lumpiness En. 
When seeing is at the best, and everything favorable, close 
attention enables one to trace nearly all these lines out beyon 
the spot and its penumbra. But they are so exceedingly er 
in the green an ue. Near D, and below it, it is much more 
difficult to see, and I am not even quite sure that this structure 
still exists in the regions around C and below it. Here, in he 
red, even with the highest dispersion and under the most favor- 
able circumstances of vision, the spot-spectrum appears simply 
as a continuous shade, crossed here and there by widened an 
darkened lines, which, however, are very few and far between 
