230 REPORTS ON THE STATE OF SCIENCE, ETC. 
CATALOGUE OF EARTHQUAKES 
| 19295-1930 
(1) In 1928 the late Prof. Turner prepared a ‘ Catalogue of Earthquakes, 
1918-1924,’ which was published by the British Association for the Advance- 
ment of Science. It was his intention to publish a further Catalogue, and 
he was engaged upon this, upon his ‘ Shallow and Deep Earthquake ’ 
research, and upon the revision of the tables within a month of his lamented 
death in Stockholm in 1930. Since then I have endeavoured to fulfil his 
wish by completing the manuscript of the Catalogue to the end of 1930, 
being the last year for which the I.S.S. is complete. The Catalogue, 
therefore, contains the statistical summary of the world’s earthquakes for 
six years, 1925-1930. This Catalogue has been compiled as voluntary 
work at home, and is offered as a contribution to earthquake science and 
as a personal memorial of respect to Prof. H. H. Turner. 
(2) A characteristic of the period 1925-1930 has been the increase in the 
number of epicentres determined and the consequent increase in the size 
of the I.S.S. on which this Catalogue is based. This increase in the 
number of epicentres is presumably or entirely due to the increase in the 
number of stations which send good readings to Oxford. Thus when the 
work was taken over from Shide in 1918 only some 120 stations were 
available, while by the end of 1930 readings are being received from over 
300 stations. The consequent increase in the number of epicentres 
determined is well shown in the following table, which is self explanatory. 
It is interesting to note that, apart from 1918, old epicentres form in the 
mean one-half the total of determined epicentres in each year. The increase 
of pages in the I.S.S. is due not only to more quakes and records being 
teceived, but to more phases being identified and included in the 
“ Additional Readings ’ given, at the end of each quake. 
Epicentres. Ratio. Pages in 
Year. New. Old. Total. New Old. 1.8.8. 
1918 171 201 372 0:85 218 
1919 III 212 323 0°52 170 
1920 III 223 334 0°50 200 
1921 103 155 258 0:67 176 
1922 119 IgI 310 0:62 222 
1923 185 359 544 0°52 316 
1924. 120 350 470 0°34 284 
1925 133 347 480 0°38 324 
1926 I51 461 612 0°33 427 
1927 167 495 662 0°34 473 
1928 177 418 595 0°42 440 
1929 217 385 602 0°56 518 
1930 207 446 653 0:46 426 
Total .. 1972 4243 6215 Ratio is 0° 465 
The increase in the number of quakes and in the number of pages of 
print appears to be maintained, subject to slight variations from year to year. 
Though the number of quakes given for 1930 (653) is 51 more than 1929, 
the number of printed pages is 92 less ; this is partly accounted for by the 
