AN earthquake of unusual strength occurred in Ross-shire and the surrounding counties on August 16 at about 2.15 a.m. (G.M.T.). The early accounts are insufficient to determine its intensity and disturbed area, but it seems to have reached the degree 7 (Rossi-Forel scale) and to have been felt over at least 10,000 sq. miles, for it was observed at such places as Glenshiel in west Boss-shire and Pitlochry in Perthshire. Its strength is also evident from the fact that it was recorded at West Bromwich, where, at about 2.25 a.m., it caused the pointer of the seismograph to move an eighth of an inch. The principal earthquake zone in the north of Scotland is the portion of the Great Glen fault that lies be tween Inverness and Loch Ness. As most of the places from wlriah reports come cluster in the neigh bourhood of Dingwall, it is possible that the origin may lie in that district.