Astrophysical Letters
Hale was interested in founding a new journal to document research in the field of Astronomy and Astrophysics. Harper also believed that publishing departmental journals was an essential element of a true University as professor's work should include research and communication as well as teaching.
In a letter to Harper, he states his idea is to "bring together a considerable amount of spectroscopic etc. literature under a single cover both by original papers, reprints and translations published at irregular intervals whenever sufficient material is at hand"
Having raised some temporary funds to get it started Hale published the first issue in 1895.