Adriaan van Maanen

On rotations in spiral nebulae:

Measurements of motions in the spiral nebula M101 [superimposed on negative image of this nebula; from the Astrophysical Journal, 44 (1916), 210-28]

First page of van Maanen's 1916 article on rotations in spiral nebulae [from the Astrophysical Journal, 44 (1916): 210-11. [Large file -- may take time to load.]