218 REPORTS ON THE STATE OF SCIENCE, ETC. 
Bulletins and Tables. 
The ‘ International Seismological Summaries’ for October to December 1919, all 
1920, and January to March 1921, have been printed and distributed. April to June 
1921 is passed for press; July to September 1921 is ready for printing, and much 
preparation has been done for subsequent months. The arrears produced by the War 
are thus being steadily caught up at the rate of printing three months’ observation in 
two months, a satisfactory result, largely due to the work of Mr. J. 8. Hughes and Miss 
E. F. Bellamy. An index list has been formed of the epicentres and times printed in 
the summaries and their predecessors from 1913 to 1920, arranged chiefly in order of 
longitude; and this has already made possible an analysis of this material for study 
of the four-year period (see below under Periodicity). 
Bound volumes of the summary were exhibited at Wembley last year and this 
year. Miss Bellamy also prepared two large maps, one showing the distribution of 
observing stations, the other the distribution of epicentres, for exhibition at Wembley, 
as mentioned in the last report. 
Depth of Focus. 
To the lists of cases of abnormal focus given in the last two reports may now be 
added— 
Group I (Hicu Focws). 
d h m 8 z 4 Depth [P] 
1921 March 6 7 24 50 265N 109:0W —-020 2 
Group III. (DrErr Focus). 
The letter R, following the figures for depth means that the depth is merely repeated 
from a former determination for the same epicentre and not deduced from the actual 
observations. 
° 
ake ate m. s. 3 a. 
1920 Jan. 20 1 42 5 80S 1275E +030R —12 
1920 Feb. 22 17 35 40 467N 1458E +-050 at 
1920 Feb. 26 1 26 O SON 1l00E 4-050 —953 
1920 Mar. 3 10 43 25 808 1275E +4030R — 
1920 Mar.15 12 5 30 2008 1765E +030 —21 
1920 Mar.22 20 1 43 1708 1775W +-040 —11 
1990 April 6 19 2 2 508 1550E +050 +413 
1990 May 6 9 40 30 440N 1310E +.070R —56 
1920 May 10 18 49 40 558 1300E +060 —26 
1990 May 27 5 49 12 5SON 1100E +-050R —143 
1990 July 2 18 41 5 708 1530E +070 —63 
1920 July 20 12 18 30 338N 1405E +010 —10 
1990 Aug. 3.03... 2... 15. ..68.N; 1280 Hi.t4-040,, see 
19290 Aug.15 8 16 33 1308 1668E +-030  —21 
1920 Nov.24 11 61.0 1438. €42W +010 . 6 
1920 Dec. 18 10 3 40 OSN 1265E +4020 —31 
1921 Mar. 4 12 60 58 290N 1390B +060  —53 
1921 Mar. 23 22 44 50) ( —63 
1901 Mer 24 1 26 of 85S 1300E +-060. hea 6 
1921 Mar.30 15 2 10 76S 1283E +040 _16 
1921 April2s 17 33 43 2208 1800 +4040 _99 
1921 May 20 0 43 10 350N 690E +030 —11 
1921 July 15 18 6 12 IN 12978E +-030 —38 
1921 Sept.20 20 21 15 158 1093E +-050 z 
1921 Oct. 10 2 6 30 50S 1350E +-060 —24 
1921 Nov. 15 20 36 30 365N 705E +030 97 
1921 Dec. 18 15 29 24 258 710W +080 —7I 
Microseisms and the Indian Monsoon. 
(By Sir G. T. Watxzr, F.R.S.) 
A letter to Nature (October 18, 1924, p. 576) by Dr. S. K. Banerji draws atten- 
tion to microseisms which were recorded by the Milne-Shaw seismograph at the Bombay 
Observatory. Some twelve years ago it was ascertained that the Calcutta seismograph 
(of Ewing-Omori pattern) recorded microseisms when a storm in the Bay reached 
