ASTRONOMY: H. N. RUSSELL 
415 
12 King, E. S., Ann. Harvard Coll. Obs., Cambridge, 76, 1915, (119). 
13 Merrill, P. W., Popular Astron., Northfield, 25, 1917, (661). 
" Adams, W. S., Astroph. Chicago, 33, 1911, (64-71). 
" Coblentz, W. W., Lick. Obs. Bulletin, Berkeley, Cal, 8, 1915, (104-120). 
" Wilsing and Scheiner, Publ. Astrophys. Obs., Potsdam, 19, 1909, (5-221). 
" Rosenberg, H., Astron. Nach. Kiel, 193, 1912, (357-370). 
i« See Harvard Annals, 64, 126-127. 
" King, E. S., Ibid., 76, 1915, (189). 
20 Hertzsprung, E., Astrophys. Jour., 42, 1915, (92-110). 
" Scares, F. H., these Proceedings, 2, 1916, (521). 
22 Shapley, H., these Proceedings, 2, 1916-17, (12-15) and 3, (267-270). 
23 King, L. v., Trans. Roy. Soc. Canada, Ottawa, 9, 1915, (99-103). 
24 Color index of {" Persei + 0.16; color index of ^ Persei + 0.03; King, E. S., Harvard 
Annals, 76, 1915, (118). Color index of o Persei; similar to that of a star of spectrum F., 
Wilsing and Scheiner, Potsdam Publ. 19, 1909, (64). 
25 Barnard, E. E., Astrophys. Jour., 41, 1915, (253-258). 
26 Coblentz, W. W., Lick Obs. Bull., 8, 1915, (121). 
27 Hertzsprung, E., Astrophys. Jour., 42, 1915, (352-356). 
28 Harvard Circular, No. 188, 1915. 
29 Cannon, Miss A. J., Harvard Annals, 91, 1918, (274), (star No. 1546). 
30 Stebbins, J., Pop. Astron., 25, 1917, (657), and earlier papers. 
31 Guthnick, P., Vierteljahrsschrift d. Astron. Gesellsch., 53, 1918, (169). 
32 Shapley, H., Astrophys. Jour., 43, 1916, (180). 
33 Cannon, Miss A. J., Pop. Astron., 25, 1917, (314). 
34 Shapley, H., Astrophys. Jour., 44, 1916, (273-291). 
36 Shapley, H., Ibid., 40, 1914, (448-465). 
36 See numerous notes by Mrs. W. P. Fleming, Harvard Annals. 56, (209-212). 
37 Adams, W. S. and Pease, F. G., these Proceedings, 1, 1915, (391). 
38 Cannon, Miss A. J., Harvard Annals, 76, 57. 
3 9 Hertzsprung, E., Astrophys. Jour., 42, 1915, (118). 
« Kapteyn, J. C, Ibid., 40, 1914, (118-126). 
« Russell, H. N., and Shapley, H., Ibid., 40, 1914, (422-423). 
42 Shapley, H., Ibid., 48, 1918, (282-287). 
43 Hertzsprung, E., Zeitschr. f. Wiss. Phot., 3, 1905, (442). 
44 Russell, H. N., Pop. Astron., 22, 1914, (275-294 and 331-357). 
45 Adams, W. S., these Proceedings, 2, 1916, (157-163). 
46 Kapteyn, J. C, Astrophys. Jour., 47, 1918, (255-275). 
47 Russell, H. N., Observatory, London, 37, 1914, (167-169). 
48 Stromberg, G., Astrophys. Jour., 47, 1918, (14). 
49 For example, the mean absolute magnitude given by Adams, {Mt. Wilson Contribution, 
No. 142) for the four Cepheid variables and eight other stars of Miss Maury's classes c 
and ac which, appear in his list, is + 0.3; and there is abundant evidence from the parallactic 
motions that the mean absolute magnitude of the stars of this peculiar class is at least as 
bright as — 2, and probably brighter. 
50 Kapteyn, J. C, Astrophys. Jour., 47, 1918, (263). 
51 Adams, W. S., Publ. Astron. Soc. of the Pacific, 27, 1915, (236). 
52 Adams, W. S., Ibid., 26, 1914, (198). 
53 Comstock, G. C, Astron. Journal, Albany, 25, 1907, (119). 
54 Barnard, E. E., Ibid., 29, 1916, (181). 
55 See summary in Monthly Not. Roy. Ast. Soc, 78, 1918, (304). 
56 LudendorfF, H., Astron. Nach., 189, 1911, (145-155). 
57 Russell, H. N., Pop. Astron., 25, 1917, (666). 
58 Eddington, A. S., Monthly Not. Roy. Ast. Soc, 79, 1918, (19). 
