[5] “Text Book of Geology,” 1882, p. 85. [6] “Aids in Practical Geology,” 1893, page 36. [7] See E. S. Dana, “Minerals and How to Study Them,” 1895, p. 154. [8] Consult “Applications of Geology,” etc., by Prof. Ansted, 1865, p. 116, _et seq._ [9] “Industrial Resources of the Tyne, Wear and Tees,” 1864, p. 204. [10] R. H. Scott, “Elementary Meteorology,” 1883, p. 137. [11] Report of British Association for 1846, Part II., p. 17. [12] Geological Magazine, N.S., Dec. III., Vol. V, 1888, pp. 26 _et seq._ [13] Such as “The Study of Rocks,” by F. Rutley: “Aids in Practical Geology,” by Prof. Grenville Cole; “Tables for the Determination of the Rock-forming Minerals,” by Prof. Lœwinson Lessing; “Petrology for Students,” by A. Harker; and especially “Microscopic Physiography of the Rockmaking Minerals,” by Rosenbusch (transl. Iddings). [14] Consult the works on petrology previously mentioned. [15] The mode of preparation of thin rock sections for examination by the microscope is described in much detail in the works of Mr. Rutley and Professor Cole previously alluded to; also in “Outlines of Field Geology,” by Sir Archibald Geikie, 1882, p. 202 _et seq._ [16] 16th Ann. Rep. U. S. Geol. Surv. (1894–95), pt. IV., p. 532. [17] 16th Ann. Rep. U. S. Geol. Surv. (1894–95), pt. IV., p. 539. [18] “Testing of Materials of Construction,” 1888, p. 438. [19] _British Clayworker_, April, 1896, Supplement, p. iv. [20] _Op. cit._ p. iv. [21] 16th Ann. Rep. U.S. Geol. Surv. Pt. IV., 1895, p. 532. [22] _Engineering News_ (U.S.), Dec. 13th, 1894. INDEX, &c. Abrasion tests, 146 Absorption of bricks, 132 Acids defined, 76 Actinolite, 69 Air, chemical composition of, 105 Albite felspar, chemical composition, 34 Almandite, 68 Aluminium, under blowpipe, 73 Anorthite felspar, chemical composition, 34 Aragonite, 49 Bases defined, 76 Basic bricks, 90 dolomite for, 55 magnesite for, 56 Biotite mica, 43 under blowpipe, 73 Black bricks, 101 Blowpipe, 58 Blue bricks, 101 Bluish-black brick-earths, 27 Boulder clay, 50 Bourges, Oxford clay of, 24 Bovey Heathfield clays, 20 Bracknell bricks, 135