NOTE.
The Syndics of the Cambridge University Press desire to express their thanks to Messrs Macmillan & Co. for their courteous permission to use in this work the steel engraving of Sir George Biddell Airy published in Nature on October 31, 1878.
The Syndics of the Cambridge University Press desire to express their thanks to Messrs Macmillan & Co. for their courteous permission to use in this work the steel engraving of Sir George Biddell Airy published in Nature on October 31, 1878.