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theory of gases. The reader will be prepared, therefore, to look with a critical eye 

 at the conclusions arrived at by the author. 



Perhaps the point of chief interest attaches to the value of the Solar Constant 

 of radiation. The careful observational data collected by the physicists of the 

 Smithsonian Institute lead to a value for this constant of i'94gm. calories per sq. 

 cm. per minute. This value has not been universally accepted, and other 

 physicists argue in favour of a value exactly double this, viz. 3*98 : they contend 

 that a large proportion of the radiation is reflected or scattered in the outer layers 

 of the earth's atmosphere. Whilst the question cannot be regarded as definitely 

 settled, the balance of evidence appears to be in favour of the smaller value. Prof. 

 Bigelow claims to have established the validity of the larger value. Before we can 

 accept his proof we should like to have some justification for his system of 

 dynamics, which forms its basis. The same reason leads us to doubt his other 

 conclusions. 



The compilation of this volume must have involved an enormous amount of 

 work. The author has collected a large mass of data and made lengthy series of 

 computations. The determination of variable constants to several decimal places 

 from ordinary observational data is, however, but labour lost. The whole volume 

 leaves one with the impression of a massive edifice built without any foundation. 



H. S.J. 



The Australian Environment (especially as Controlled by Rainfall)^ By 

 Griffith Taylor, D.Sc, B.E., B.A., F.G.S., F.R.G.S., Physiographer 

 in the Commonwealth Bureau of Meteorology. [Pp. 188, with 15 contour 

 maps in colour, a solar-control model, and 167 other maps and diagrams.] 

 (Commonwealth of Australia, Advisory Council of Science and Industry, 

 Memoir No. 1. Melbourne, 1918.) 



The sub-title of this memoir is, " A regional study of the topography, drainage, 

 vegetation, and settlement ; and of the character and origin of the rains," and this 

 sub-title adequately explains the purpose of the memoir. It is one of a series 

 dealing with the climatic control of settlement in Australia, and follows logically 

 upon an earlier memoir in which the effects of temperature and humidity on 

 settlement were investigated , in an attempt to decide which portions of the 

 continent were most suitable for white settlement. 



The climate of Australia is peculiarly suitable for study in this manner. This 

 is due to the fact that Australia offers the widest stretch of low and level land in 

 the world, which is affected by the trade wind. This results in many phenomena, 

 such as seasonal rainfall, being presented in their least complex form. Thus, 

 the relationship between the motion of the sun in declination and the seasonal 

 variation in rainfall is remarkably close : it has been illustrated by the author by 

 means of an ingenious solar-control model. In this way he links up the rainfall 

 areas, pressures, storm systems, and permanent winds. 



Other subjects discussed, which are of particular importance to the agricultural 

 settler, are rainfall " reliability " and rainfall " uniformity." A place with high 

 rainfall reliability is one in which the percentage variation in any year of the total 



ainfall from its mean value is small ; a place with a high rainfall uniformity is one 

 in which the amount of rainfall is well distributed throughout the year. In some 

 parts of Australia the rainfalls are very erratic from year to year and also from 

 month to month. It is shown that, from this poirit of view, the Perth region is 



one of the most suitable for settlement. 



