Note 1 — Chapter XXIX · THE CARBONIFEROUS VOLCANOES OF ENGLAND
Reading edition
Sedgwick, Trans. Geol. Soc. 2nd series, iii. part 1 (1826-28), p. 63; Trans. Cambridge Phil. Soc. ii. (1822), p. 21. Sir J. Lowthian Bell, Proc. Roy. Soc. xxiii. (1875), p. 543.