[171] See Trevithick's letter, 7th May, 1815, vol. i., p. 364.
[172] See patent specification of 1802, vol. i., p. 128.
[173] Drawing of iron steamship, vol. i., p. 336.
[174] a, steam-case; b, boiler-case; c, space for condensation of steam; d, water and steam space; e, fire-tubes; f, fire-box; g, fire-door; h, fire-bars; i, ash-box; j, ash-box door; k, air-tubes in condenser; l, chimney; m, water level; a smoke-jack fan draught.
[175] See Trevithick's letters, July 8th, 1815, vol. ii., p. 80, and 7th, vol. i., p. 364; and 16th May, vol. i., p. 370; and patent of 1815, vol. i., p. 375.
[176] See vol. i., p. 104.
[177] See patent specification, vol. i., p. 128.
[178] See Trevithick's letter, 13th Jan., 1811, vol. ii., p. 6.
[179] See vol. ii., p. 71.
[180] See chap. xx.