METEOKOLOGY WATER. 415 



The congealing point as given by De Negri and Fabris (+8 to +16° C.) is 

 deemed probably due to a typographical error. 



Alcohol from agaves, A. Pedroso {Jour. Agr. Trop., 11 (1911), No. 116, 

 p. 64; abs. in Internat. Inst, Agr. [Rome^, Bui. Bur. Agr. Intel, and Plant Dis- 

 eases, 2 (1911), No. 3, pp. 677, 678).— The results of a test show that 360 liters 

 of alcohol were obtained from 2,160 liters of Agave rigida elongata, or hene- 

 quen juice, with a specially prepared yeast. The preparation of alcohol from 

 the juice of zapupe is also mentioned. 



METEOEOLOGY— WATER. 



Relation of temperature and rainfall to crop systems and production, J. F. 

 VooRHEES ('J'cn»essee Sta. Bill. 91, pp. 23, figs. 16). — A number of charts pre- 

 pared from reports of the Weather Bureau of this Department are given which 

 show the length of the growing season from the last killing frost in spring to 

 the first in fall, and the distribution of rainfall in Tennessee and other Southern 

 States as well as in the north Central States. The meteorological conditions, as 

 shown by these charts, are discussed with reference to the growth of crops in 

 Tennessee and other States, more particularly the relation between climate and 

 the double cropping system of the South. 



In this system as practiced at the Tennessee Station and to a greater or less 

 extent by the most successful farmers in the State " the winter cover crop is 

 sown during the comparatively dry months of September and October and oc- 

 cupies the ground through the wet months of winter and early spring. It is 

 ready to be turned under for green manure in March or April or to be cut for 

 forage during May, which is drier than the months either before or after it 

 and offers the most favorable opportunity for harvesting one crop and putting 

 in another. This second crop put in in May covers the ground during the wet 

 summer months, protects it from washing rains when they are most frequent, 

 and is ready to harvest during the drier months of fall. In extending this 

 study to cover the States east and south of Tennessee, it was found that the 

 conditions are more favorable for the double-cropping system over this region 

 as a whole than they are in Tennessee where the system originated." The 

 system is especially adapted to the Southern States because it conserves the 

 rainfall during the wet periods which occur both in winter and in summer 

 and brings crops to maturity in the dry spring and fall periods. 



Crop rotations which are suited to the double cropping system are described. 



The influence of the weather on the quality of barley, potatoes, and 

 sugar beets, A. Hecker (Landw. JahrJ)., Jfl (1911), No. 3-Jf, pp. J{17-526, 

 figs. 3). — Data for sums of temperature, sunshine, and rainfall from April 

 to October, 1883 to 1907, for 11 stations in beet and barley growing regions are 

 given and correlated with the yield and quality of barley, potatoes, and sugar 

 beets. 



With reference to barley, the conclusion was reached that a dry July is 

 favorable to the quality of the grain. Moderate, somewhat less than normal, 

 moisture combined with medium or perhaps below normal temperature affords 

 the surest guaranty of good results in yield and quality, and it is safe to say 

 that cool June, and especially July, weather is favorable to good quality. The 

 effect of weather conditions is accentuated to a marked degree by the character 

 of the soil. The poorer soils are not only directly but also indirectly unsuited 

 for the culture of brewing barley. 



In case of potatoes it was found that very wet weather injured the quality. 

 Very dry weather affected especially the quantity, but also reduced the quality. 

 Dry weather followed by wet was very unfavorable to the quality, and wet 



