[1] The general questions capable of a single treatment for England, Scotland and Ireland are considered under [United Kingdom].
[2] Measurements made on a map on the scale of 12½ m. to 1 in., the coast being assumed to run up estuaries until the breadth became 1 m., and no bays or headlands of less than 1 m. across being reckoned. The coast-line of Anglesea and the Isle of Wight, but of no other islands, is included.
[3] A separate topographical notice is given under the heading [Wales], but the consideration of certain points affecting Wales as linked with England is essential in this article.
[4] The figures given here are for the ancient or geographical counties. Section IX., on Territorial Divisions, indicates the departures from the ancient county boundaries made for certain purposes of administration. Each county is treated in a separate article in the topographical, geological, economical and historical aspects. Further topographical details are given in separate articles on the more important hill-systems, rivers, &c.
[5] Partly belonging to Scotland.
[6] The principal members of the Humber-system are the Ouse of Yorkshire (121 m. long from the source of the Swale or Ure) and the Trent (170 m.), qq.v. for their numerous important tributaries.
[7] Including the Medway (680 sq. m.) in the drainage area.
[8] Including the Wye (1609 sq. m.) and the Lower Avon (891 sq. m.) in the drainage area.
[9] These rivers have their earlier courses in Wales, and flow at first to some point of east. Of wholly Welsh rivers only the Towy and the Teifi are comparable in length and drainage area with the smaller rivers in the above list (see [Wales]).