He also worked in a hospital and had a good knowledge of astronomy.

He wrote some other works also on the field of astronomy.

In 1908 he became professor of astronomy at the university.

In addition to his research and teaching, he has written many books on the history of astronomy.

"National Members" are usually people with a high level of professional astronomy.

For that, however, a very complete knowledge of astronomy was necessary.

Almost all aspects of astronomy are considered in these two books.

He appears also to have been familiar with the study of astronomy.

"The whole of astronomy is built on not knowing anything."

Today's meeting may well become a landmark in the history of astronomy.