Notice of the Occurrence of an Earthquake along the Northern Edge of the Granite of the Dartmoor District on the 28th of September, 1858.

On the evening of Tuesday, the 28th Sept. last, a slight shock of an earthquake was felt in the district adjoining the northerly edge of Dartmoor; and it appears to have been almost entirely confined to the vicinity of the junction of the granite and the Carbonaceous rocks. Crediton is the most north-easterly point at which, as far as I can gain information, the occurrence was noticed. No vibration of the ground was there felt, but a rumbling noise was heard, attributed at the time to a supposed explosion of the Gunpowder Mills on Dartmoor. No such explosion, however, had taken place. Crediton is on the spur of New Red Sandstone that extends thence in a westerly direction, by Bow and North Tawton, to Exbourne; this last place is situated about four miles to the north of Okehampton. No vibration or sound was noticed at either of the three last-named places, or to the south of Crediton, at Exminster, Kenton, Star Cross, or Teignmouth, all on the same geological formation. The Carbonaceous rocks lie to the west, between the New Red Sandstone and the granite of Dartmoor, which they adjoin on the east, north, and west sides. .At Chudleigh and Hennock, both onthe Carbonaceous rocks, no sound nor vibration was perceived on the 28th; but at Trusham, to the north of Chudleigh, on the same formation, on the evening of Thursday the 30th, a noise was heard,which a person who had resided in a country subject to earthquakes immediately recognized