He then became assistant at the Hamburger Sternwarte ( Hamburg Observatory ) , then located at Stadtwall , and in 1862 was appointed director .
He was astronomer at the observatory at Durham , England , from 1853 to 1856 .
astronomer then became assistant at the Hamburger Sternwarte ( Hamburg Observatory ) , then located at Stadtwall , and in 1862 was appointed director .
He was astronomer at the observatory at Durham , England , from 1853 to 1856 .