METEOROLOGY WATER. 1011 



tions form a part. The rainfall durinj;; the period named was 9..32 in. The 

 recorded evaporation at the station on a dry rocky knoll was only 0.85 in. 

 less than the rainfall, at the station in low swampy ^ronnd 4.48 in. less, and 

 at the station in the experiment jiarden about 50 ft. away from the second 

 station 2.7S in. less. 



The evaporimeters used consisted of " a pint fruit jar, tightly corked with 

 a cork stopper soaked in paraffin. Through the stopper a glass tube extends 

 from the bottom of the ,iar up andtthrough a second cork, which tightly closes 

 the opening into a porous clay thimble. The glass tube extends to the top of 

 the thimble. For further protection against the entrance of water from with- 

 out a paraffined piece of cloth was titted tightly around the glass tube, and 

 extended as a roof over the top of the fruit jar. 



'• The jar was filled with distilled water up to zero mark, and the porous 

 thimble and the glass tube were also filled with distilled water. Each evapo- 

 rimeter was sunk into the ground to the level of the top of the fruit jar. As 

 evaporation took place from the surface of the thiml)le the water rose from 

 the jar up through the glass tube, thus keeping the thimble full and lowering 

 the surface of the water in the jar. The rate of evaporation varied with the 

 relative humidity of the surrounding air, and the amount was measured by 

 carefully pouring more distilled water into the jar from a graduate, until the 

 water surface in the jar rose again to the zero mark. The amount of water 

 necessary to accomplish this was the measure of the amount of evaporation 

 for the given period." 



Studies on the rate of evaporation at Reno, Nev., and in the Salton sink, 

 F. H. Bk^klow (Xat. Geogr. Mag., 19 (1908), No. 1, pp. 20-28, figii. -'/).— The 

 partial filling of Salton sink by the overflow of the Coloi-ado River, as well as 

 the means adopted for stopping the overflow, are described, and an account is 

 given of preliminary observations on the jjhysicai factors involved in evapora- 

 tion which were made at Reno, Nev., with a view to more intelligent planning 

 of large-scale observations on evaporation from the Salton Sea. The general 

 plan of the proposed observations in the latter region is briefly described. 



Influence of plant cover on the temperature and humidity of the lower 

 strata of the air, A. Luboslavski {Met. Vpestnik, 1907, No. 1; ahs. in Zhur. 

 Opuitn. Agron. [Russ. Jour. Expt. Landiv.], S {1907), No. Jf, pp. ^77, ^78). — The 

 author states that at the present time it may be considered as established that 

 in the absence of any cover the surface of the soil undergoes wider temperature 

 variations than the air. If the surface of the soil is covered by vegetation 

 these temperatui'e conditions of the soil are transferred to the surface of the 

 plant cover. 



Observations by the author and his pupils carried on since 1897 fully cor- 

 roborate this view and show that the surface of a grass cover is actually the 

 point of a sharp bend in the curves of the distribution of the temperature dur- 

 ing the hours of snnliglit as well as during the night hours when radiation is in 

 excess. As a result of the heating and cooling of the surface of the plant cover 

 the relative and absolute humidity are so distributed that at given hours the 

 humidity increases to the very surface of the soil cov(>red l)y plants. Over 

 the plants the absolute as well as the relative humidity is always greater than 

 over bare soil. At night, even when the humidity is near saturation, the tem- 

 perature botli over the grass and in the grass is lower than in tlie layers of air 

 lying somewhat liigher or lower. The author concludes, therefore, that the 

 cooling is obviously a consequence of radiation alone and not of evaiioration as 

 some investigators think. 



Distribution of the temperature in the lower layers of the air in the pres- 

 ence of woody plants, L. Ruuovirz (Jit/. \ inatitiU. 1907, So. 2; abs. in Zhur. 



