H,— 34,

Notes on Tropical Storms and other Disturbances, 1934-35. December 27th, 1934 : Cyclone of moderate intensity in Tonga. Barometer 29-24 in. at Keppel Island. January 22nd, 1935 : Tropical cyclone in the New Hebrides. February, 1935 : Tropical cyclone near Rarotonga during the second week. March 20th, 1935 : A cyclone moved across the Tonga Islands. Atmospheric Electricity. A continuous record of the gradient of potential in the air was obtained from a Benndorf selfrecording electrometer at the Land Station. Absolute measurements of the gradient were made in October using the method of the stretched wire.

Monthly Mean Values of Atmospheric Potential Gradient, Apia Observatory, Samoa, 1934.

Tides. A tide-gauge was maintained at the Lagoon Station, giving continuous records of the depth of water there. Tabulations of hourly values and of times and depths of high and low water were sent to the United States Coast and Geodetic Survey, Washington, D.C., U.S.A. Time Service. The standard clock, Strasser and Rohde No. 381, was controlled from time to time by wireless time signals from Annapolis, U.S.A., and later, when the wireless set had failed, by transit observations with the Heyde transit telescope. The " Synchronome " clock provided time signals for the magnetographs and seismographs, using current from groups of dry cells.

108

(The units are volts per metre.) Jan. Feb. Mar. April. May. June. July. Aug. Sept. Oct. Nov. Dec. Year. 97 120 114 131 112 121 128 ! 117 119 115 121 111 117 '