just enough water to raise the level to the normal point. The quantity of water admitted is accurately measured by the use of a tipping-bucket, similar to those employed in recording rainfall. Each tip of the bucket is recorded electrically on a register that may be located some distance away. The supply of water is drawn from a closed vessel, so arranged as to show the gross amount of water delivered to the tipping-bucket, thus affording a check on the record.
In the complete design a second electrical valve and tipping-bucket draws off, measures, and records any excess of water above the normal level caused by rainfall. This part of the apparatus was not required at the Salton Sea, and is not shown in the illustration.
MARVIN C. F., "Measurement of Precipitation," 2d ed., Washington, 1903. ( United States Weather Bureau, Circular E, Instrument Division.)
Many valuable papers on rainfall and rainfall measurement have appeared in the annual volumes of British Rainfall, London, 1860 to date. See list in the 1900 volume, pp. 42-45.
SUPAN ALEXANDER, "Die Verteilung des Niederschlags auf der festen Erdoberfläche," Gotha, 1898. ( Petermanns Mitteilungen, Ergänzungsheft No. 124.) The tables herein are the chief collection of rainfall normals for the world at large, exclusive of Europe.
HELLMANN G., "Die Niederschläge in den norddeutschen Stromgebieten," Berlin, 1906, 3 vols. A vast compilation of collected data and normals of precipitation for the greater part of Germany and extensive areas of contiguous countries. Vol. I contains elaborate analysis of special features of the precipitation; a bibliography (pp. 31-36); and a detailed rainfall chart of Germany.
WILD H., "Die Regen-Verhältnisse des russischen Reiches," St. Petersburg, 1887. With atlas.
ELIOT SIR JOHN, "The Rainfall of India," Calcutta, 1902. (Indian meteorological memoirs, v. 14.)
GREAT BRITAIN, METEOROLOGICAL OFFICE, "Rainfall Tables of the British Islands, 1866-1890," London, 1897. (Official, No. 114.)