I got to know many things about Mobius and his works from this book. For example, what cause him to think about the famous Mobius function and Mobius inversion formula. Also, there are facts that support J.B. Listing(1808-1882) as the first inventor of the Mobius Band. In the first half of 19-th century, many leading mathematicians made a living as astronomers, because mathematics at that time had not been accepted as an independent scientific field!