1B17] SOILS FERTILIZERS. 617 



Rain and snowfall of Canada, 1903-1913, R. F. Stupakt (Ottaiva: Govt., 

 1914. pp. 207). — Tlie rainfall and snowfall records published in the annual 

 reports of the Meteorological Service of Canada for the years 1903 to 1913, 

 inclusive, are reprinted and bound together in this report. 



Temperature observations during the year 1914, Elizabeth Stephansen 

 (Be/-. Norges Landbr. Hoiskoles Virks., 1914-15, App., pp. 29, figs. 3). — Daily 

 readings of temperature at Aas, Norway, during 1914 are compared with 

 normals for the period 1874 to 1914. The temperature of the soil at depths 

 of i, A, and li mm. is compared with that of the air. 



Temperature changes due to terrestrial radiation and relation of the latter 

 to plant growth, G. Rcstek {Atti R. Accad. Econ. Agr. Georg. Firenze, 5. ser., 

 13 {1916), No. 1, pp. 1-27; abs. in Inteniat. Iitst. Agr. [Rome], Intemat. Rev. 

 Sci. and Pract. Agr., 7 (1916). Xo. 7, pp. 931,, &35).— This article discusses the 

 question of the placing of thermometers in the open air in order to get read- 

 ings which are truly repi*esentative of the actual temperature conditions to 

 which plants are subjected, and various observations are reported which 

 indicate the wide differences in temperature which may be due to comparatively 

 small differences in the position and elevation of the thermometers. For 

 example, it was observed that a thermometer placed under the dense shade 

 of a carob tree showed minimum temperatures 3 to 4° C. higher than those 

 of a thermometer in the open air. A thermometer 20 in. above the ground 

 receiving all the heat of direct solar radiation as well as soil radiation showed 

 a daily range of temperature approximating 40°. Observations with two ther- 

 mometers, one 20 in. above the ground and unprotected and the other 55 in. 

 above the ground but protected from the sun and terrestrial radiation, 

 showed the minimum daily temperature in case of the thermometer nearest 

 the ground. The annual mean of 470 observations was 19.2° for the higher 

 thermometer and 16.6° for the lower. The absolute minimum for four years 

 was 11.6° for the first and 6.4° for the second. The monthly mean difference 

 of temperature was 2.3° and the absolute maximum difference was 5.4°. 



It is held that " these results prove beyond question the importance of the 

 study, in connection with vegetation, of the temperature changes due to terres- 

 trial radiation, which are perfectly distinct from the general cooling of the 

 atmosphere and occur in the lower air strata, the medium of plant life." 



SOILS— FERTILIZERS. 



Agricultural geology, R. H. Rastaxl {Cambridge, Eng.: University Press, 

 1916, pp. IX-i-S31, figs. 51). — The purpose of this book is to supply information 

 on those parts of geologj' which are of direct interest to the agriculturist. The 

 most space is devoted to a study of the soil, and this is treated primarily from 

 the geological standpoint. The later chapters of the book contain a summary 

 of the distribution of the rock formations of tlie British Isles and the characters 

 of the soils yielded by them. 



On taking samples of soil for soil surveys, E. J. Russeix {Joiir. Bd. Agr. 

 [London], 23 {1916}, No. If, pp. 3^2-349). — General information on points to be 

 considered in taking soil samples for surveys of English soils are given. 



[Soil studies], F. W. Mokse {Massachusetts Sta. Circ. 64 {1916), pp. 3).— 

 This circular is intended to supplement Circular 45 of the station (E. S. R., 32, 

 p. 321), and describes a plan by which county agents of the extension service 

 can cooperate with the station in making soil examinations more serviceable. 

 It is considered especially desirable to compare the texture and composition of 

 soils of known value for special crops with those of soils believed to have 

 similar possibilities. A method of sampling with a soil auger to be uniformly 

 used is described, and an outline of factors useful in soil classification is given. 



