De la Rue's 13-inch telescope. This reflector telescope was built in 1850 by the British astronomer Warren de la Rue (1815-1889). With this telescope, De la Rue made many drawings of astronomical objects. The telescope was first mounted in an observatory at Canonbury, London, and then at Cranford, Middlesex, England. In 1873, De la Rue retired from active astronomy and donated his instruments to the observatory at the University of Oxford.