620 EXPERIMENT STATION RECORD. [Vol.35 



between the occurrence of summer fog and the distribution of the redwood 

 {Sequoia sempervirens) in California. In addition, a result of the fog is 

 easily seen wherever there are single trees, such as is the case on the Berkeley 

 Hills of the coast ranges, which are in process of reforestation. During the 

 summer fogs the small trees are dripping with moisture, although the ground 

 away from the trees is perfectly dry. As a result the grass beneath each tree 

 remains green throughout the year." 



Tlie climate of Eoumania in relation to dry farming, L. Geobgesco {Vie 

 Agr. et Rurale, 6 {1916), No. 11, pp. 191-194, fia^. 2; abs. in Rev. Sci. [Paris], 

 54 (1916), II, No. 13, pp. 405, 406). — It is explained that the climate of Rou- 

 mania is typically continental and on the plains is such a« to make the use of 

 dry-farming methods desirable. The annual rainfall is seldom less than 500 

 or more than 800 mm., the mean being about 600 mm. (about 23.6 in.) It is 

 smaller on the plains (300 to 500 mm.), and increases with the elevation (1,300 

 to 1,600 mm. in the mountains). It also varies in distribution seasonally. 



Even in seasons of low rainfall the amount is sufficient for good wheat crops, 

 provided it is suitably distributed. The average annual temperature is about 

 10° C. (50° F.) on the plains and from 8 to 9° at the higher elevations. There 

 are, however, wide seasonal extremes in temperature (—35 to 40°). The daily 

 extremes are also wide. Cold, high winds are common in winter, and dry, hot 

 winds in summer. Bright sunshine varies from 50 to 80 per cent of the total 

 possible. The humidity of the air varies from 50 to 60 per cent in summer 

 and from 85 to 90 per cent in other parts of the year. The climatic conditions 

 are such as to make early seeding in the fall and late seeding in the spring 

 necessary. 



The influence of weather conditions upon the amounts of nitrogen acids 

 in the rainfall and atmosphere in Australia, O. Masson, V. G. Andebson, D. 

 A\TEEY, and H. A. Hunt {Rpt. Brit. Assoc. Adv. Sci., 1915, pp. 87-94, figs. 3).— 

 This is a preliminary report upon the organization of investigations covering 

 the whole of Australia (16 stations), similar to those reported by Anderson 

 for the region of Melbourne (E. S. R., 33, p. 617). The plan and purpose of 

 this work and the apparatus and methods to be used are briefly described. 



Discussion on smoke abatement and air pollution (Rpt. Bril. Assoc. Adv. 

 Sci., 1915. pp. 387-393 ) . — Brief notes are given on discussions at the Manchester 

 meeting of the British Association for the Advancement of Science, 1915, on 

 the work of the Manchester Air Pollution Advisory Board, the work of the 

 Sheffield Health Committee, damage to vegetation caused by atmospheric pol- 

 lution by smoke, improvements in domestic fire grates, recent improvements 

 in gas fires, and other aspects of the smoke question. 



sons— FERTILIZERS. 



Soil temperature, G. J. Botjyoucos {Michigan Sta. Tech. Bui. 26 {1916), pp. 

 133). — A continuation for three years of the field experiments previously noted 

 (E. S. R., 29, p. 618) is reported, together with the final conclusions drawn from 

 the entire investigation. 



" The field studies on the temperature of different types of soil, namely, 

 gravel, sand, humus loam, clay, and peat at 6-, 12-, and 18-in. depths, showed 

 that when the surface of all these soils was covered with a thin layer of sand 

 they had almost exactly the same average temperature throughout the year 

 except during a short period in the spring when thawing was taking place. 

 . . . During the summer months the peat [had] a monthly average tempera- 

 ture of a few tenths of a degree higher than the mineral soils. In the fall, the 

 sand and gravel possessed a slightly higher monthly average temperature than 



