Sir George Biddell Airy ( 27 July 1801 â `` 2 January 1892 ) was an English mathematician and astronomer , Astronomer Royal from 1835 to 1881 . Sir George Biddell Airy PRS KCB ( 27 July 1801 â `` 2 January 1892 ) was an English mathematician and astronomer , Astronomer Royal from 1835 to 1881 .