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occurrence of earthquakes, followed by publication of a paper on this subject; (2) preliminary investigation of the Observatory tilt records for the period 1930 to 1934, and the preparation of a report for publication. The improvements to some of the seismograph stations recently carried out have enabled some definite progress to be made with the study of local earthquakes and related problems, but some additional well-equipped stations are required. Mr. Jones has made a detailed study of the data provided by recent local earthquakes, and has prepared some material for publication. At the same time Dr. Bullen has also been working on this problem, using earlier data. There appears to be reasonably good agreement between different investigators as to the general nature of the crustal structure in the New Zealand region, but a determination of the actual thickness of the various layers, the focal depths of local earthquakes, and the velocity of seismic waves cannot be satisfactorily carried out without some additional stations with sensitive local recorders and accurate timing apparatus. Steps are being taken to establish additional stations on these lines. Dr. Bastings has been working on the determinations of south-west Pacific epicentres and related problems in co-operation with the Observatory. Geophysical Work. —Mr. Watson-Munro carried out radioactive investigations from time to time during the year. In February and March he was engaged in magnetic work in the Eotorua district in connection with a survey of the volcanic and thermal regions by Dr. Arthur L. Day, of the Carnegie Institution of Washington. Mr. Jones was engaged in magnetic work in the Takaka-Collingwood district during part of January and February. These officers have furnished reports of their geophysical work direct to the Secretary of the Department. Officers of the Geophysical Survey were stationed at the Observatory during the latter part of the year. Workshop. During the year the Observatory workshop has been improved by the addition of a Driver electric-power drilling-machine, and a Starrett dial-test indicator, as well as tools and other small appliances. During the first part of the year the construction of a new Imamura strong-motion seismograph was carried on, and the work was completed in June. Further work on the construction of seismographs was interrupted owing to the workshop being required for urgent work on the apparatus for the geophysical survey during the latter part of the year. A large amount of instrumentmaking work is at present in hand. The maintenance of a workshop at the Observatory has the advantage of enabling instruments to be constructed at considerably less cost than otherwise, and, in addition, urgent repairs can be carried out on the premises with a minimum loss of time. Publications. The Observatory has continued to publish a monthly cyclostyled seismological bulletin giving readings from all New Zealand seismograph stations. The bulletins published during 1937 cover the period 1936 January-April and 1936 December-1937 November. The following Observatory bulletins were also published during 1937 : — Bulletin 108. —A Subsoil Survey of Wellington City. (L. Bastings.) Bulletin 111.—The Seismicity of New Zealand Cities and Towns. (R. C. Hayes.) Bulletin 118. —Observations during the Disappearance of the Rings of Saturn, June, 1936. (I. L. Thomsen.) Bulletin 119. —Tables for the Reduction of Apparent Travel-times of P and S Seismic Waves. (K. E. Bullen.) Bulletin 120.—The Position of New Zealand Aurorse. (M. Geddes.) Bulletin 121. —The Seismological Aspects of the Wairoa Earthquake of September 16, 1932. (R. C. Hayes.) Bulletin 123. —The Hawke's Bay Earthquake of 1921, June 29. (K. E. Bullen.) Bulletin 124. —Earthquakes and Atmospheric Pressure (2nd paper). (R. C. Hayes.) Bulletin 125.—Annual Report of the Dominion Observatory for 1936. Bulletin 126. —Some Seismological Aspects of the Buller Earthquake —Part 111. (L. Bastings.) Bulletin 127.—Some Seismological Aspects of the Buller Earthquake —Part IV. (L. Bastings.) An article on " Earthquakes in New Zealand " was prepared for the " New Zealand Official YearBook," 1938, and articles on " Time Service Arrangements " were prepared for the Year-Book and for the "New Zealand Nautical Almanac." Staff. During 1937 the following officers were engaged in the Observatory work : Mr. I. L. Thomsen, Observatory Assistant; Mr. C. M. N. Watson-Munro, Observatory Assistant; Mr. W. M. Jones, Assistant Seismologist; Mr. G. S. Marshall, Instrument-maker ; Miss K. R. Tullett, Shorthand-typiste. R. C, Hayes, Acting-Director.

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