WITHIN little more than sixteen months, the Indian Empire has been visited by another great destructive earthquake. On May 31, at about 2.45 a.m. (probably about 9.15 p.m. on May 30, G.M.T.), the cities of Quetta, Mastung and Kalat were almost entirely razed to the ground. In Quetta alone, the loss of life is estimated at more than 20,000. The region is one that has frequently been disturbed by destructive earthquakes. The valuable report by Mr. W. D. West on those of August 25 and 27, 1931, has recently been noticed in NATURE (April 27, p. 661). The earlier shock had its centre near Sharigh, which lies 39 miles east of Quetta; the later and stronger near Mach, 26 miles south-east of the same city. In the recent earthquake, the epicentral area if we may take it as lying along the Quetta-Mastung-Kalat line is roughly parallel to the zone joining Sharigh to the main part of the Mach area, and about 50 miles to the west. It is also parallel to the main structural lines of the country, and especially to the great boundary fault, 45 miles to the west, that runs along the west side of the Khojak Range for a distance of at least 120 miles. It was to a nearly horizontal shift of about 2J ft. along this fault that the severe earthquake of December 20, 1892, was due.