1044 EXPERIMENT STATION RECORD. 



of the region, the first marked by conditions which supported a dense population 

 (of the neolithic period), the second by desert conditions, and the third, or present 

 period, in which the land is gradually assuming a steppe-like character. 



The gradual desiccation of the region advanced from the Soudan, but to-day the 

 rainbelt is again extending more and more toward the north. On the steppes, where 

 the Soudan merges into the Sahara, the annual rainfall is 6 to 12 inches and supports 

 considerable vegetable and animal life. 



Texas rainfall during- 1905 ( Texas Farm and Ranch, 25 (1906), No. 10, p. 3, fig. 

 1). — A map with brief notes furnished by E. E. Spencer, director of the Texas sec- 

 tion of the Weather Bureau, is given. The average annual precipitation for the 

 State as determined from reports of 87 stations was 44.49 in., or 12.55 in. above the 

 normal. The greatest annual precipitation was 86.32 in. at Jefferson, the least 17.8 

 in. at El Paso. The heaviest rainfall occurred over the eastern, northeastern, cen- 

 tral, and coast regions of the State. 



Rainfall in the agricultural districts, G. G. Boxd (Queensland Agr. Jour., 16 

 (1906), No. 5, p. 380). — A table is given which shows the total rainfall for each month 

 from December, 1904, to December, 1905, inclusive, in 41 agricultural districts of 

 Queensland. 



The relation of forests to rainfall, W. F. Hubbard (Mo. Weather Rev., 34 (1906), 

 No. 1, pp. 24-26, figs. 2). — The distribution of forests as dependent upon rainfall is 

 illustrated by conditions in California, and it is shown that "topography and winds 

 are the controlling factors in the distribution of forests. They make most of the 

 Pacific coast a region of winter rains and summer droughts, and, away from the 

 coast, limit the forests to the higher altitudes. ... As rainfall determines the 

 presence or absence of forests, so the configuration of the land and its relation to 

 w r ater bodies and constant winds determine the rainfall." 



Forests and rainfall in Silesia, J. Schubert (Ztschr. Forst u. Jagdiv., 37 (1905), 

 No. 6,j)p. 375-380, figs. 3; abs. In Met. Ztschr., 22 (1905), No. 12, pp. 566-570, figs. 3, 

 and Science, n. ser., 23 (1906), No. 589, p. 593).— This subject is discussed on the basis 

 of the rainfall map published by Hellmann in 1899, the conclusion reached being that 

 forests seem to produce an increase in precipitation. This is ascribed to the fact that 

 forests retard wind movement and promote rise and cooling of the air. If one-half 

 of the observed difference is set down as being due to the increased protection of the 

 gauges set up in or near the forests, the actual effect of the trees themselves would 

 roughly correspond to an increase in altitude of 40 meters. 



Prevention of damage by frost, E. P. Skinner (Mo. Weather Rev., 34 (1906), 

 No. 2, pp. 79, 80). — Tests of various smudges and the use of potash salts as fertilizers 

 are reported, which, while not conclusive, indicate that more or less protection may 

 be afforded in some cases by such means. 



Cloud studies, A. W. Clayden (London: John Murray, 1905, pp. XII1+184, pis. 

 61 ; rev. in Nature [London], 73 (1906), No. 1896, pp. 416, 417, figs. 2).— In his review 

 of this book Prof. H. H. Hildebrandsson states that it will be a standard work for 

 all students of clouds. The author accepts the types of the International Cloud Atlas 

 and arranges his various forms as subforms of these types with the exception of the 

 nimbus cloud, which he classifies as a subform of the stratus type. 



On cloud formation in the Alpine valleys. —Contributions to the mechanism 

 of cloud formation, II. vox Ficker (Ber. Nat urn: Med. Yer. Innsbruck, 29 (1903-4, 

 1904-5), pp. 193-275). — A series of observations at various elevations to study especially 

 the formation of stratus clouds in inland valleys is reported. 



Apparatus for observing and recording storms (Sri. XX. Steele, 1905, Aug. 

 15, Sup.; abs. in Rev. Sci. [Paris], 5. ser., 5 (1906), No. 9, pp. 278, 279). — An appara- 

 tus devised by A. Turpain, of the meteorological observatory of Puy-de-D6me for 

 photographically and automatically recording the electrical condition of the atmos- 

 phere during storms is described. 



