812 EXPERIMENT STATION RECORD. 



ing the theory of various forms of ordnance for this purpose, particularly the 

 different forms of acetylene cannon first introduced by Magj^iora Graziani. of 

 Italy. The advantages of this system are quite fully explained. 



Studies of the annual precipitation of the Continent of Africa, G. Fraun- 

 DERGEB {Mitt. Justus Perthes' Geogr. Anst., 52 {1906), Xo. .'/, p/>. 73-82, map 1). — 

 The available data on this subject are compiled, and a colored map showing the 

 geographical distribution of rainfall is given, with discussions of the general 

 rainfall characteristics of the continent and of different typical districts as fol- 

 lows : Eastern Sahara, Guinea coast region and hinterland, Congo and Orange, 

 east side of longitude 25° and British East Africa, Somaliland, Abyssinia. 

 Egyptian Sudan, and Egyjit. 



Climatology of South Africa (Quart. Jour. Roy. Met. Hoc. [Londo^i], 32 

 {1906), No. 139, pp. 239, 2JiO).— This is an abstract of a paper by C. Stewart 

 before the British Association at its Cape Town meeting, summarizing quite 

 fully the climatological conditions of South Africa, based upon the observa- 

 tions of a considerable number of stations scattered over the I'egion. 



The chief factors controlling the climate are stated to be ocean currents and 

 elevation. A remarkable feature is the great imiformity in mean annual tem- 

 perature, this being about r>2° throughout the region. " This is due to decrease 

 of temperature with increase of elevation above sea-level, almost neutralizing 

 the increase of temperature which would otherwise occur with increased 

 intensity of solar radiation due to a nearer approach to the (Mjuator." 



The temperature of the coastal regions varies with relation to the ocean 

 currents. South Africa is divided ifito three rainfall areas " (1) winter rain- 

 fall ax-ea in the west, (2) constant rains (small area) in south, and (3) summer 

 rains in the east." There was little evidence in support of tlie " south-east rain " 

 theory, especially for the coastal areas. In the cape peninsula the largest 

 t:mount of sunshine occurs in summer; in the plateau regions in winter. 



Present day climates in their time relation, F. M. Ball (Mo. Weather 

 Rci\, 3'i {191)6), Xo. .'). pp. 201-205). — A l)rief review of some of the more 

 important facts regarding climatic changes with special reference to geo- 

 logical changes. 



It is stated that while we must conclude fi'om all the scientific data avail- 

 able that all climates remain invarial)le. " the most elementary knowledge of 

 geology and related e;irth sciences is sufficient to prove that climates have 

 changed many times in the geologic ages through which the earth has passed. 

 All theories accounting for such changes lead irresistibly to the conclusion 

 that climates to-day must l)e changing, although not in any measurable 

 amoiuit." 



Cold waves and frost in the United States, E. B. Garriott ( V. 8. Dept. 

 Agr., Weather Bur. Bui. P, pp. 22, chitrts S2H). — "The paper notes briefly 

 the general distribution of the colder areas of the Northern Hemisphere, 

 refers to general conditions that are associated with cold waves, and presents 

 a chronological account of historical cold i)eriods in the United States. It 

 then summarizes and classifies the moi'e important cold waves and frosts 

 that occurred from 1888 to 1902, inclusive, and -presents 328 charts that 

 exhibit the meteorological conditions that attended the principal cold waves 

 of that period." 



The thermal anomalies on the earth's surface, F. Hopfner {Mitt. Justti.'i 

 Perthes' Geogr. A list.. 52 {1906), Xo. 2, pp. 32-36, chart 1). — New normal 

 monthly and annual isotherni;'l lines for the different hemispheres similar 

 to those of Dove a are calculated and charted to show thermal anomalies and 



oDie Verteilung der Warme auf "der Oberflache der Erde (Berlin, 1852). 



