Imperial Valley press., 1908-09-12

mined from temperatures at Tndfo and those deduced from the water eleva- ton of the sea, is probably mainly due to wind effect upon the water elevation at the Salt Creek gage. It seems probable that the gage read ings at that point show elevations that are too low by 0.2 to 0.S 1t. for June I and July 1, 1907, and elevations that are about 0.5 to 0.4 it. too high on Sept. i, Oct. 1 and Nov. 1, and 01 to 0.2 it. too high on Dec. i.
 By assuming that wind or some otaer cause is accountable for the larger part of the inconsistencies in the observed monthly rate of evapo- ration at Salton Sea, and smoothing out the rate curve based on observa- ton, it is possible to predict, from the single year record. probable rates of evaporation from Salton Sea.
 These rates indicated are equiva- lent to 6.12 it. per year, which is, as a matter of course, in substantial ac- cord with the evaporation determined from the oecreasing elevation of Sal ton Sea, above noted, at GA it. for the 12 months April i, 1907. to April l, 1908.
 It is known, however, that the tenn perature for these 12 months was 0.4 degrees below the normal tempera- ture at Indio and 2.9 degrees below the normal at Mammoth Tank south east of Salton Sea; therefore without doubt to some extent below normal at Salton Sea.
 According to estimates made by Prof. Grunsky the evaporation from Salton Sea from April 1, 1907, to April 1, 1908, should have been 6.54 it., and the normal annual evaporation should be 6.70 it. If later observations show that the sea has had an appreciable effect upon temperature then even the small discrepancy between the value, 6.54 it., estimated, and GA it., here tofore noted as observed, may disap- pear Tn this event, suitable factor for temperature reduction resulting from the creation of a new body of water may have to be introduced.
 He says: Tt may De that closer approximation to actual evaporation from large water surface could have been made by giving the results of observations in the pan floating in the river at Kingsburgh still greater weight than herein above noted.
 Special evaporation studies are about to be made in the Salton Basin by the U. s. Weather Bureau, under cooperation of the U. S. Geological Survey and the U. $. Reclamation Ser vice. These will, it is expected, de- termine with precision the actual evaporation by months and years from the Salton Sea. The direct obser- vations to accomplish this should in clude, at least three times per month, simultaneous water-surface observa tions at opposite ends of the sea. But the information sought that will be of greatest value to the engineer will be the relation that the evaporation thus ascertained from a large open water surface bears to experimental obser vations, made with small pans, placed upon the open ground with no more protection against sun and wind than will result from sinking the pans into the grOunu to such depth that their water-surfaces will conform to the ground level. Incidentally, the great range of temperature, the dryness of the air, .the insignificant rainfall and the small, easily measured inflow in to the Salton Sea should make the Salton Basin studies extremely valua- ble in determining the best formulas for estimating evaporation from known meteorological conditions"