1 84 



NATURE 



[October 15, 19 14 



the birth- and death-rate of Italy; Prof. F. Filomuse- 

 Guelfi, with modern idealism and the philosophy of 

 law; Prof. A. Fracassini, the beginnings of the 

 struggle of the Roman Empire against Christianity. 



The meeting of the society lasted for five days, from 

 Monday, September 22, to Friday, September 26, 1913. 



RAINFALL OBSERVATIONS. 



A USEFUL discussion by Prof. A. G. McAdie on 

 -^*- the rainfall of California forms No. 4, vol. i., 

 of the University oj California Publications in Geo- 

 graphy. The data used are chiefly the records of the 

 U.S. Weather Bureau and extend for some localities 

 over a period of sixty-three years. Among the chief 

 factors controlling the rainfall of the State may be 

 mentioned its diversified topography, the prevalent 

 westerly winds from the Pacific Ocean, and the rela- 

 tively cold California current. For convenience of 

 discussion, the State has been divided into five sec- 

 tions, bearing some relation to the principal water- 

 sheds, and for each division are given the notable 

 climatic features and a general statement of the dis- 

 tribution of rainfall and of its variation with altitude, 

 while more detailed information is shown by tables 

 and plates. Summer in California is practically rain- 

 less, but for other seasons certain portions of the 

 State are considered by the author as lying within 

 the zone of maximum intensity of rainfall in the 

 United States. The greatest annual amount during 

 the past ten years was 153I in. in Del Norte County, 

 and amounts exceeding 100 in. have occurred at many 

 places. Apparently the heaviest monthly fall in the 

 United States (71 J in.) occurred at Helen Mine (Cal.) 

 in January, 1909. The rainfall of San Francisco is 

 dealt with in considerable detail ; the annual mean 

 (sixty-four years) was 22-6 in., maximum yearly fall 

 38*8 in., minimum 93 in. The longest drought was 

 175 days in the summer half year of 1903. 



As a supplement to " Rainfall Observations " for the 

 year 1912, the Norwegian Meteorological Institute 

 has published a volume (with charts) giving mean and 

 extreme values of rainfall since its establishment to- 

 wards the end of 1866. During the first few years 

 of its existence the stations were few, but in 19 12 the 

 number reached 492. The tables include inter alia 

 five-yearly means for 1876-1910, normal monthly and 

 yearly values and extremes and days of rain and snow 

 for the total number of years available, with sum- 

 maries of days with amounts varying from o-i to i-o 

 mm. The charts include normal yearly values 

 (isohyets) for 1876-19 10. These show very clearly the 

 effect of storms and topography upon the rainfall. 

 The curves along the south-west and west shores, 

 which lie in the direct track of cyclonic depressions, 

 show that the normal amounts range from 1000-1600 

 mm., while in districts not far inland amounts of 

 2000-3000 mm. are not unusual. In the more 

 northerly and inland parts the values range from 

 600-1000 mm., and still less, especially in the extreme 

 north-eastern districts. The work is a very valuable 

 contribution to the climatology of an extensive tract, 

 reaching beyond the 71st parallel of latitude. 



The report of the director of the Egyptian Meteoro- 

 logical Service (Mr. J. I. Craig) on the rains of the 

 Nile Basin and the Nile flood of 1912 follows the 

 general lines of its predecessors. During the year 

 rainfall was measured at 112 stations, and that re- 

 corded at 143 other places was taken into account. 

 On the whole of the year rains were in excess on the 

 eastern slopes of East Africa and of the Red Sea, but 

 norrnal to weak everywhere else. The differences 

 from the mean, and the average deviations by dis- 

 tricts, are shown by tables, as usual. Mr. Craig 



NO. 2346, VOL. 94] 



states that the low stage of the river in 1912 was 

 very poor, and that lower gauges were touched on the 

 Bahr el Jebel than ever before. The flood was late; 

 it was not until the beginning of August that the 

 gauge at Wadi Haifa rose above normal, after which 

 it continued so until August 21. A chapter is devoted 

 to the extension of the usual equation for the flow of 

 water in open channels, to include all the factors 

 which affect the discharge, and the theory is applied 

 to calculate the losses on the White Nile in the be- 

 ginning of the year in question. The report concludes 

 with the readings of the chief river gauges in Egypt 

 and the Sudan. 



THE AUSTRALIAN MEETING OF THE 



BRITISH ASSOCIATION. 



SUB-SECTION A. 



COSMICAL PHYSICS. 



Opening Address by Prof. E. W. Brown, F.R.S., 

 Chairman of the Sub-Section. 



To one who has spent many years over the solution 

 of a problem which is somewhat isolated from the 

 more general questions of his subject, it is a satisfac- 

 tion to have this opportunity for presenting the 

 problem as a whole instead of in the piecemeal' fashion 

 which is necessary when there are many separate 

 features to be worked out. In doing so, I shall try 

 to avoid the more technical details of my subject as 

 well as the temptation to enter into closely reasoned 

 arguments, confining myself mainly to the results 

 which have been obtained and to the conclusions 

 which may be drawn from them. 



In setting forth the present status of the problem, 

 another side of it gives one a sense of pleasure. When 

 a comparison between the work of the lunar theorist 

 and that of the observer has to be made, it is neces- 

 sary to take into consideration the facts and results 

 obtained by astronomers for purposes not directly 

 connected with the moon : the motions of the earth 

 and planets, the position of the observer, the accuracy 

 of star catalogues, the errors of the instruments used 

 for the measurement of the places of celestial objects, 

 the personality of the observers — all these have to be con- 

 sidered; in fact, almost every one of the departments 

 of the astronomy of position must be drawn upon to 

 furnish necessary data. The time has now arrived 

 when it may perhaps be possible to repay in some 

 measure the debt thus contracted by furnishing to the 

 astronomer, and perhaps also the student of geodesy, 

 and, if I may coin a word, of selenodesy, some results 

 which can be deduced more accurately from a study 

 of the moon's motion than in any other way. A long- 

 continued exploration with few companions which ulti- 

 mately leads to territories where other workers have 

 already blazed paths gives the impression of having 

 emerged from the thick jungle into open country. 

 The explorer can once more join forces with 

 his brother astronomers. He can judge his 

 own results more justly and have them judged 

 by others. If, then, an excuse be needed 

 for overstepping the limits which seem, by silent con- 

 sent, to have been imposed on those who devote them- 

 selves to lunar problems, it consists in a desire to 

 show that these limits are not necessary and that a 

 study of the motion of the moon can be of value and 

 can contribute its share to the common funds of 

 astronomy. 



The history of the motion of the moon has been 

 for more than two centuries a struggle between the 

 theorists and the observers. Ever since the publica- 

 tion of the " Principia " and the enunciation of the 

 law of gravitation by Isaac Newton, a constant effort 



