layer of water four or five miles in depth it would still remain a most exceptional occurrence. Volcanos as we know them pour forth their lavas and vapours slowly. That an eruption should have occurred of such stupendous power and with such suddenness as to generate a considerable seawave capable of crossing the Indian Ocean is a remarkable circumstance. It is believed to be the only one of the kind of which history has preserved any authentic record.

APPENDIX

DE MONTESSUS DE BALLORE'S TABLES OF THE DISTRIBUTION OF SEISMICITY

THE

HE following tables are of such value that it has been thought desirable to publish them entire. They constitute a great advance in the branch of seismology which treats of earthquake distribution. They are published in Beiträge zur Geophysik, vol. iv., under the title, “Introduction à un essai de description sismique du globe et mesure de la sismicité." The observations are brought down to the year 1897 in those districts in which the seismic occurrences have been most frequent and best observed and include in all 131,292 quakes and 10,499 epicentres. Especial care has been taken not to use the same quake twice and to exclude from each district all quakes which originate elsewhere. With the growth of observation many of the results may require modification. The tables formulate only the results of existing data reliably observed and recorded.

TABLE OF SEISMIC REGIONS CLASSIFIED BY GRAND DIVISIONS OF THE WORLD AND NUMERICAL DATA RELATING TO THEIR SEISMICITY

DESIGNATION OF COLUMNS

1. Number assigned to the district in each grand division.

2. Names of the districts.

3. Number of epicentres or of localities so considered. 4. Number of quakes reported from the district.

5. Period covered by the observations.

h-historic.