﻿Vol. 6 1.] LEICESTER EARTHQUAKES OF 1893 AND 1904. 3 



the two foci. 1 In this respect, the Leicester earthquake of 1893 

 resembles the twin-earthquakes of Hereford in 1896 and Derby in 

 1903 and 1904. 



III. Earthquakes oe June 21st, 1904. 



On this day there were two undoubted earthquakes, the first 

 and weaker at about 3.30 a.m., the second at 5.28 a.m. 



a. June 21st, 1904 : about 3.30 a.m. 



Intensity, 3. Number of records 2, from 2 places. 



The only records of this shock come from Groby and Markfield, 

 at each of which localities a slight quiver was felt. The epicentre 

 was probably near these places, both of which are close to the south- 

 eastern margin of the north-western epicentre of the earthquake of 

 1893. 



b. June 21st, 1904 : 5.28 a.m. 



Intensity, 5 ; centre of isoseismal 5, in lat. 52° 35*2' N., long. 0° 59-5' W. 

 Number of records, 249, from 130 places, and 56 negative records from 

 44 places (map, p. 4). 



Time of Occurrence. 



The total number of records of the time is 215, 18 of which, 

 lying between 5.25 and 5.32, are regarded by their observers as 

 accurate to the nearest minute. The average of these estimates is 

 slightly over 5.28 a.m., which agrees with the time given by a 

 signalman at Lowesby station (6 miles from the epicentre). 



Isoseismal Lines and Disturbed Area. 



The continuous lines on the map (p. 4) represent isoseismal 

 lines of intensities 5 and 4. The isoseismal 5 is 23 miles long, 

 17 miles wide, and 314 square miles in area, its longer axis running 

 N. 42° W. and S. 42° E. The centre of the curve is about half-a- 

 mile north-east of Burton Overy : its distances from the probable 

 epicentre of the previous shock being about 12 miles, and from the 

 south-eastern epicentre of the earthquake of 1893 (measured parallel 

 to the isoseismal axes) about 3 miles to the north-west. 



The outer isoseismal, of intensity 4, is 33| miles long, 26 miles 

 wide, and 681 square miles in area, its longer axes being directed 

 from N. 44° W. to S. 44° E. Its distance from the isoseismal 5 is 

 3 miles towards the north-east, and 5| miles towards the south- 

 west. 



The shock was also felt at 15 places outside this isoseismal and 

 within, though close to, the boundary of the sound-area (represented 

 on the map by the dotted line). The disturbed area was thus 43 

 miles long, 36 miles wide, and covered about 1200 square miles. 



1 The greater intensity of the first part of the shock at Uppingham was, 

 no doubt, due to the proximity of that place to the south-eastern focus. 



B 2 



