475
INDEX.
page | |
Trap, of Trotternish, the alternation only apparent, and this is probably the case in all other instances of such supposed alternation | 181 |
──────────────, columnar on a large scale | 181 |
──────────────, generally composed of augit and felspar | 182 |
Trees, found in the marsh lands near London | 302 |
Tunnel of the Tavistock canal, description of the | 146 |
─────────────────────, accuracy in the direction of the drift, its length and ventilation while making | 155 |
Tweed, account of the beds on the banks of the | 90 |
Trotternish in Sky, its rocks described | 178 |
Veins, numerous and chiefly of porphyry traverse the slate of Cruachan | 118-121 |
──── of trap sometimes occur in the slatc of Cruachan | 118-123 |
──── of Huel Peever described by Mr. Williams | 139 |
──── of copper and tin run from north-east to south-west | 148 |
──── that do not run north-east and south-west, generally unproductive of metal and seem of newer formation | 148 |
──── occur but in few sorts of rocks | 151 |
──── run through all the strata | 151 |
──── at Morwel Down, their dip | 151 |
────, general notice of such as are productive near Morwel Down | 152 |
────, filled by infiltration | 395 |
────, porphyritic. See Porphyritic veins | |
Vegetable remains in chalcedony, Dr. Mac Culloch on | 398 |
Ventilation of the drift for the Tunnel of the Tavistock canal, reference to account of | 155 |
Warburton, Henry, Esq. Note on Magnesian breccia | 205 |
──────────── On some beds of Shell-marle in Scotland | 305 |
Whernside, height of | 435 |
William, John, Junr. Esq. Account of some remarkable disturbances in the veins of Huel Peever in Cornwall | 139 |