H.—34

DOMINION OBSERVATORY. REPORT OF THE DOMINION ASTRONOMER AND SEISMOLOGIST FOR THE YEAR ENDED 31st DECEMBER, 1933. Buildings and Equipment. The buildings and equipment have been kept in good order and condition. The Observatory grounds have been kept in good order by the Wellington City Corporation. Astronomy. Time Service.—The Observatory signal clock has been controlled mainly by the reception of radio time signals. A special series of meridian transit observations was carried out during October-November, 1933, in connection with the international longitude programme. Observations were made with No. 1 transit instrument on every clear evening during the period, and daylight transits were also taken when weather permitted ; 365 transits of stars were observed, and 63 special radio time-signals were received.

Reception of Radio lime Signals.—The following radio time signals have been received for the purpose of checking the Observatory signal clock : —

* Special signals in connection with international longitude programme during October-November. Differences from Observatory clock not yet available. f Large difference apparently due to an error in PKX signal, t Large differences due to an error in Observatory clock caused by the strong local earthquake on November 2 d. 17 h. G.M.T. § Large difference apparently due to an error in NPM signal. The total number of radio signals received during the year was 920. The signals received comprise both mean time and rhythmic signals from Nauen, Norddeich, Malabar, Bordeaux, Rugby, and Saigon ; and mean time signals only from Honolulu, Annapolis, and Arlington. It is not possible to make regular use of the British time signals from Rugby radio, owing to the unsuitable times of transmission (5.30 a.m. and 9.30 p.m. N.Z.M.T.). In connection with the reception of radio time signals, the Marconi magnetic drum recorder was installed at the Observatory during the year. The recorder was first used on November 17, when the Honolulu (NPM) time signal at 3 h. G.M.T. was automatically recorded on the tape chronograph. Time Signals sent out from the Observatory.—The time service has been maintained as previously, and the regular time signals sent out. The present routine at the Observatory provides for the following time signals, most of which are sent automatically by the Observatory clock, the error of which seldom exceeds a quarter of a second of time. Automatic time signals have been sent to — (1) The General Post Office and the Railway Department, Wellington, by telegraph daily, except on Sundays and Government holidays. (2) Ships and to the general public at Wellington, by electric lights at the Observatory, daily : (3) The Auckland Harbour Board, by electric lights at Auckland, on Tuesdays and Fridays, except on Government holidays : (4) The South Island telegraph offices, by telegraph, on Tuesdays and Fridays, except on Government holidays :

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Call Sign and Hour Nu^® r ° f Greatest observed Error of Observatory Station. W avc. (G.M.T.). | Clock. —— — I _ Nauen .. .. DFY (LW) 00 i 193 0 46 seconds fast, June 1st. Norddeich .. DAN (SW) 00 ! 73 0-30 seconds slow, July 26th. *Malabar .. .. PKX (LW) 0030 19 Malabar .. .. PKX (LW) 01 139 1-99 seconds fast, August 29th.f Honolulu .. .. NPM (SW) 03 100 0-45 seconds slow, August 15th. Arlington .. .. NAA (SW) 05 i 1 0-05 seconds fast, October 4th. Arlington .. .. NAA (SW) 08 ! 20 0-29 seconds slow, November, 19th. Annapolis .. .. NSS (LW) 08 11 0-28 seconds slow, March 31st. Bordeaux .. .. FYL (LW) 08 141 0-41 seconds slow, August 15th. Rugby .. . • GBR (LW) 10 28 *Saigon .. .. FZA (LW) 118 Nauen .. .. DFY (LW) 12 8 Rugby .. .. GBR (LW) 18 1 0-54 seconds slow, November 2nd. J Saigon .. .. FZA (LW) 19 1 0-76 seconds slow, November 2nd. j Annapolis .. .. NSS (LW) 21 47 0-38 seconds fast, January 1st. Arlington .. .. NAA (SW) 21 65 0-59 seconds fast, October 22nd. Honolulu . • NPM (LW) 24 65 5-59 seconds slow, October 8th.§