H.— 22

20

VII. REPORT OF THE GOVERNMENT ASTRONOMER. Hebtor Observatory, Wellington, New Zealand, L9tb June, 1920. The '['lime Smevice, The usual duties in connection wiih the t-ime service have been attended to throughout (lie year. The equipment is Considerably out of dale, as reported on in previous reports, and should be improved as soon as possible. It lias been necessary to suspend the time service fairly frequently whenever the errors of the clocks became too great to allow accurate time signals to be Supplied. Radio Time Signals, Iv'erepi ion of radio time signals: As staled in my last report, an order has been placed for the pin-chase of a modern high-power outfit for receiving , radio time signals ill the Observatory. This is urgently required; and it is expected that the difficulties of obtaining it will soon lie overcome. Transmission of radio time signals: This matter has received further attention, and a direct circuit has been erected between the Observatory and the Wellington radio station on the Tiuakori Hills. The Observatory dock', through this Circuit, automatically sends the time signals from the Wellington radio station. The service is provisional until the rest of the apparatus can be obtained and installed, and will be in operation on Tusedays and Fridays unless bad weather prevents the necessary observations from being obtained. Sbiskglooyi An order has been placed for a new Milne-Shaw seismograph to be installed al this Observatory. This will provide for one horizontal component. To complete tin , installation another Milne-Sha,w seismograph for the other horizontal component, and a vertical component seismograph, are required. An improvement has been made in the time control of the seismograph by putting in a switch on the lighting circuit. The seismograph light is cut off by hand by this switch five times a day, so thai Ihesc accurate signals on the seisniogram are used to check the lime on the record. The signals are made from the standard clock, and are always accurate to the nearest second of lime. The new seismograph-detector* has been photographed on glass, and is used on the records to assist in the identification of tin: various earth-waves. Its use has already proved a great economy in these investigations, and has materially reduced the time formerly taken to interpret the records. The tilt, of the ground is frequently recorded on the seismograms, and to obtain an independent check of this sensitive spirit-levels have been mounted east and west and north and south on the seismograph table, and are read daily. Already many evidences of lilt have been obtained. Publications and Libeakt, The following bulletins of I he Observatory have been published and distributed : Bulletin 24",- —Tables of Mathematical Functions, by C. E. Adams; Harmonic Analysis of Tidal Observations and the Prediction of Tides, by C. I']. Adams; Photographs of the Solar Corona,, by C. E. Adams; Determination of the Position of the Moon by Photography, by C. E. Adams; Daylight-saving , , by C. E. Adams. Bulletin 25.-—Annual Report of the Government Astronomer, Ist July, l!)l!). Bulletin 2(3.—Astronomical Notes: The Origin of New Stars, by A. (J. Gifiord. Bulletin 27.-The Origin of New Stars: the Dynamics of Celestial Encounters) by A. C. Clifford. Bulletin 28.—The Interpretation of a Typical Seisniogram, by George llogben ; Astronomical Notes : The Absorption of Spectra of I he Novae, by A. C. (lil'ford; Occupations of a Star by the Planet Jupiter in 1920, by Arthur Burn'ct. Bulletin 2i). —A Graphical Solution of one Case of Spherical Triangles; also, a New Method of Solving some Spherical Triangles by Plane Trigonometry, by C. W. Adams. 11 is again a pleasing duty to acknowledge the gifts of many valuable publications from other observatories. Some of these are sent in exchange for Ihe Observatory bulletins. Staff. (loverninent Seismologist: The Observatory suffered a severe loss in the death on (he 26th April, 1920, of George Hogben, C.M.G., M.A., F.G.S., F.N.Z.lnst., who was the Government Seismologist for many years. It was lo Mr. llogben that tin , inception of the seismological service of New Zealand was due, anil in his advocacy for (lie establishment of Ihis important service he was ably supported by the late Sir James Hector, 1 , '. U.5.. and the late Professor L'\ W. Hutton. 1 ,, .U.5. In 1888 two Milne seismographs were obtained by the Government ; one of these was in charge of Mr. llogben at Timaru, and the other was in charge of Sir James Hector in Wellington. Later on when Mr. Hogben moved to Wellington he brought the Milne seismograph wilh him, and the other one was lent to the Magnetic Observatory al Christehurch. For some years Mr. Hogben had the seismograph installed at his residence in Tinakori Road, but on his retirement from his position as Director of Education in 1 !)!."> Ihe seismograph was installed at the Hector Observatory, and is in charge of the Observatory. Mr. C. E. Adams, D.Sc, F.R.A.S., was appointed Government Seismologist in succession to the late Mr. Hogben as from Ist June, 1920.

* G. Hogben, Journal of Science and Technology, 1920, Vol. li, p. 110.