SOILS FERTILIZERS. 811 



Why some winters are warm and others cold in the eastern United States, 

 W. J. IIUMiMiKiCYS (Mo. Wcutlicr Rev., J,> {IDUf), Xo. 12, pp. 6'72-(;7V7).— Auioug 

 the general facts and conclusions of this iiaper are the following: 



"(1) Some winters in the eastern United States are unusually mild and 

 others exceptionally cold. (2) During mild winters this part of the country 

 temporarily has a marine climate, during cold ones a continental climate. (3) 

 The type of winter climate, marine or continental, in this section is largely 

 determined by the presence or absence of the Bermuda 'high.' (4) Persistence, 

 during winter, of the Bermuda ' high ' gives to the eastern United States a 

 marine and, therefore, for it, an unusually mild climate. Continued absence 

 of this 'high' during winter, allows a continental climate and, therefore, 

 exceptionally low temperatures, to extend quite to the Atlantic coast. (5) The 

 cause of the Bermuda ' high ' seems to be a cold-water surface, a minimum sur- 

 face temperature, along the belt of highs. (6) This low surface temperature 

 in the region of the Bermudas may depend upon the temperature and strength 

 of the Labrador current." 



Predicting minimum temperatures for frost protection, J. W. Smith (Ohio 

 Nat., 15 (1915), No. 3. pp. Jt05-40S, fig. 1). — This article explains a method by 

 which the fruit grower can closely estimate the probable minimum temperature 

 at critical periods. The method is based upon the average afternoon median 

 temperature. Explicit rules to follow in the use of the method under different 

 conditions are given. 



Climate and meteorology of Australia, H. A. Hunt (Off- Yearbook Aust., 

 7 (1901-1913). pp. 59-S5, figs. 9).— As in previous years (E. S. R., 30, p. 511) 

 the more important meteorological and climatic features of Australia are de- 

 scribed, and detailed data for temperature, pressui'e, precipitation, evaporation, 

 and other phenomena for 1912 and preceding years are tabulated. 



SOILS— FERTILIZERS. 



Soil erosion in the South, R. O. E. Davis (U. S. Dept. Agr. Bui. 180 (1915), 

 pp. 23, pis. 9, fig. 1). — This bulletin discusses the conditions affecting soil 

 erosion as observed in a field study through the States of Virginia, Tennessee, 

 Missouri, Mississippi, Alabama, Georgia, South Carolina, and North Carolina. 



It is stated that owing to climatic, economic, and soil conditions, and the type 

 of agriculture practiced, the South is especially susceptible to excessive erosion. 

 " Methods of prevention should be practiced wherever hilly land is used for 

 crops. Terracing is the best and most efficacious method, but should be supple- 

 mented by deep plowing and the incorporation of organic matter when permissi- 

 ble. The agricultural problem involves the adoption of proper crop rotation in 

 connection with preventive methods best suited to soil conditions and crop pro- 

 duction. The reclamation of eroded land is possible, but requires careful atten- 

 tion and patience. The use of such land for forestry is commonly advisable. 

 Nature effects reclamation, but the process is slow and tedious." 



See a previous note by the author (E. S. R., 31, p. 316). 



Analysis of Florida muck soils, R. E. Rose (Ann. Rpt. State Chem. Fla., 1914, 

 pp. 21i-33). — The results of analyses of saw grass muck soils of the St. John's 

 Valley, in St. Lucie County, are discussed with observations on the fertility of 

 Everglade soils In general. 



Geography of the soils of Georgia, F. A. Merrill (Ga. State Normal Sehool 

 Bui., pp. 13, figs. 3). — This buUetin discusses the geographical distribution of 

 the soil-forming rocks of the State of Georgia. 



In the Appalachian highlands argillaceous and calcareous shales and lime- 

 stones abound, the former producing red and brown loams and the latter a gray 



