Graphs

Manuscripts                       The number of tidal manuscripts per year, from 1820 to 1900.

Synthetic Network       The main synthetic network of correspondents including Bunt, Dessiou, Ross, Stratford,

                                            Whewell    Lubbock    Beaufort    &    Airy

Harmonic Network    The main harmonic network of correspondents including

                                            Adams     Darwin    Thomson    Baird    &    Roberts

American Network     The early American network of Bache, Gordon and Pourtales.