| 1. | In 1935, he completed his Ph.D. in astrophysics at Yerkes Observatory. En 1935, il reçoit son Ph.D en astrophysique à l'observatoire Yerkes. |
| 2. | There he was able to use the 40-inch (1,000 mm) telescope at Yerkes Observatory. Il pourra alors utiliser le télescope de 100 cm de l'observatoire Yerkes. |
| 3. | He was a student of Subrahmanyan Chandrasekhar while working at University of Chicago's Yerkes Observatory. Il fut étudiant de Subrahmanyan Chandrasekhar alors qu'il travaillait à l'observatoire Yerkes de l'université de Chicago. |
| 4. | He joined the Yerkes Observatory in Wisconsin, where he was an observer and an optician. Il travailla tout d'abord à l'observatoire Yerkes dans le Wisconsin, où il fut observateur et opticien. |
| 5. | He accepted a position at the Yerkes Observatory in 1924 and worked there until his retirement in 1939. Il accepta un poste à l'observatoire Yerkes en 1924 et y travailla jusqu'à sa retraite en 1939. |
| 6. | In 1915, as World War I was raging, he was invited to come to work at Yerkes Observatory. En 1915, alors que la Première Guerre mondiale faisait rage, il fut invité à travailler à l'observatoire Yerkes. |
| 7. | In 1911, he came to the United States to work as a volunteer in an unpaid capacity at Yerkes Observatory. En 1911, il vint travailler aux États-Unis comme volontaire sur un poste non rémunéré à l'observatoire Yerkes. |
| 8. | At Yerkes Observatory he was the successor to the late E. E. Barnard, inheriting Barnard's collection of photographic plates. A l'observatoire Yerkes il fut le successeur de feu E. E. Barnard, héritant de la collection de plaques photographiques de Barnard. |
| 9. | As a graduate student at Yerkes Observatory he worked under William Morgan with fellow graduate student Don Osterbrock. En tant qu'étudiant de niveau universitaire à l'observatoire Yerkes, il travailla sous la direction de William Morgan avec son camarade étudiant Don Osterbrock. |
| 10. | He married Hannah Steele Pettit, who was an assistant at Yerkes Observatory, and received his Ph.D. from the University of Chicago in 1920. Il épousa Hannah Steele, assistante à l'observatoire Yerkes, et obtint son Ph.D. à l'université de Chicago in 1920. |