ii8 



NATURE 



[July 28, 1910 



point is the proved value of green manuring, for which 

 ■purpose Erythriim spp. (Dadap) and Crotalaria striata were 

 found to be most suitable. 



The exhibition at Shepherd's Bush has naturally 

 ■created an interest in the methods and craft of " Japanese 

 gardens." Judging from an illustrated article in the July 

 number of Irisli Gardening, a typical and most successful 

 ■example of such a garden has been laid out at the TuUy 

 nurseries, Kildare, which to those interested would certainly 

 ■repav a visit. It is explained that such gardens are purely 

 pleasure resorts, and therefore the practice displayed therein 

 is entirely distinct from the methods adopted in ordinary 

 and agricultural gardens, in which the Japanese are fully 

 alive to the value of intensive cultivation. 



The first three numbers of the current volume of the 

 Bulletin of the American Geographical Society contain a 

 detailed examination of trade routes in the economic geo- 

 graphy of Bolivia, by Prof. Isaiah Bowman. The author 

 deals at length with the resources and population of 

 Bolivia in relation to the natural features of the country, 

 and concludes that, in spite of the fact that 90 per cent, 

 ■of Bolivia drains to the Atlantic and 10 per cent, is interior 

 basin drainage with no outlet whatever to the Pacific, 

 ■nevertheless, geographical position and the distribution of 

 ■resources and climate are here equally powerful factors 

 with topography. The Atlantic slope, and not the Pacific 

 slope, is, and will long remain, the back door to Bolivia ; 

 for the section of the country in which the population is 

 'found looks to the Pacific, and the first essential of all 

 the trade routes is a short line to the coast. 



Mr. W. Joerg examines the present state of our know- 

 ledge of the tectonic lines of the northern part of the 

 Cordillera of North America in a paper published in the 

 Bulletin of the American Geographical Society (p. 161). 

 Basing his discussion chiefly on the summary contained in 

 the final volume of Suess's " Antlitz der Erde," the 

 author suggests the recognition of the Alaskides, as a 

 separate province of major rank, as a subdivision of the 

 Cordillera. This would give three divisions : the northern 

 -Cordillera or Alaskides, the central Cordillera, and the 

 southern Cordillera or Lower California and the Mexican 

 Highland. The boundary between the first and second 

 would be the zone of coalescence, and between the second 

 and third the depression along Salton Sink, the Gila, and 

 the Rio Grande. 



The director-general of Indian observatories has issued 

 a memorandum, dated June 9, on the meteorological con- 

 ditions prevailing before the south-west monsoon of igio 

 (June to early October). Dr. Walker has pointed out that 

 the rainfall in India brought by this monsoon is apparently 

 affected by previous conditions over a large part of the 

 earth's surface, and that it is only when these are strongly 

 favourable or otherwise that a definite forecast is justified. 

 One of the many favourable signs is, as a rule, the pre- 

 valence of high barometric pressure in South America and 

 of low pressure in the Indian Ocean prior to the period of 

 fhe monsoon. At Buenos Aires pressure was in e.xcess in 

 March, April, and May last, but in the Indian Ocean con- 

 ditions appeared to have been, on the whole, slightly 

 unfavourable. From these and other factors specified in 

 the memorandum the inferences drawn are that there 

 appears to be no cause for expecting a large excess or 

 defect in the total amount of monsoon rainfall. The rains 

 are likely to be less steady than usual, especially those due 

 to the Arabian Sea current. Rainfall due to the Bay cur- 

 rent is likely to be, on the whole, more plentiful by com- 

 NO. 2126, VOL. 84] 



parison with the normal than that due to the Arabian 

 Sea current. 



At the international meteorological conference at Inns- 

 bruck (September, 1905) Prof. Hellmann stated that the 

 important question of the comparison of the barometers of 

 the various meteorological institutes had engaged the atten- 

 tion of several conferences, but had not been solved in a 

 satisfactory manner. Dr. Koppen also pointed out that so 

 long as the differences between barometric standards are 

 unknown, discontinuities arise when isobars are drawn for 

 large areas. The conference finally arranged that the 

 necessary work involved by such comparisons should be 

 subdivided among the chief institutes, and the result of 

 the part undertaken by the Prussian Meteorological Office 

 is contained in one of the useful papers by Dr.' Hellmann 

 in the report of that institute for 1909. The comparisons 

 of the standards at the central ofifices of the various German 

 and some foreign systems show that at some stations 

 (especially Potsdam and Zurich) the barometers agreed 

 closely with the Berlin instrument, while others showed + 

 differences of appreciable amount, the greatest being 

 0-246 mm. (nearly o-oi inch). The larger differences are 

 thought to be due to the mercury having become unclean ; 

 at all events, the results have justified the expense and 

 care bestowed upon the somewhat laborious work. 



We have received separate copies of several papers by 

 Prof. S. Lussana, of the University of Siena, which have 

 appeared recently in // Nuovo Cimento. One of them 

 deals with the coefficients of compressibility and of dilata- 

 tion with temperature of certain pure metals and alloys. 

 The coefficients were measured by means of a dilatometer 

 containing the material enclosed in a metal case. The 

 change of volume was measured by the change of resist- 

 ance of a platinum wire in the capillary tube of the dilato- 

 meter as mercury was forced along the tube by the con- 

 traction of the material. The values obtained allow the 

 difference between the specific heats at constant pressure 

 and temperature, respectively, to be calculated. For pure 

 metals the difference increases as the temperature rises, 

 but for alloys it in general decreases. In nearly all cases 

 it decreases with increase of pressure. The bearing of 

 Prof. Lussana's work on the improvement which has been 

 introduced into the law of Dulong and Petit by the sub- 

 stitution by Prof. Richarz of the specific heat at constant 

 volume for that at constant pressure will be obvious to 

 our readers. 



In an article on the renewal of sulphated storage cells, 

 reproduced from the Electrical World in the Electrical 

 Review for July i, Mr. J. O. Hamilton describes a method 

 of dealing with such cells which has proved very successful 

 at the Kansas State College. If on test the efficiency of 

 a cell sinks to 50 per cent, or lower, the plates are re- 

 moved and washed thoroughly with distilled water. They 

 are then placed in a cell containing a 2 to 5 per cent, 

 solution of caustic soda in water, and the charging current 

 sent through the cell in the usual way. If the sulphate on 

 the positi%^e plate does not disappear in the time of the 

 ordinary charge, and the solution gives an acid reaction 

 with litmus paper, more caustic soda must be added to 

 the solution, and the charging continued until the plate 

 has the usual chocolate appearance. The plates should 

 then be removed from the soda solution, well washed, 

 replaced in the sulphuric acid solution, and the charging 

 continued until gassing begins. Many cells have had their 

 efficiencies raised from 25 to 75 per cent, by six hours' 

 charge, and Mr. Hamilton considers that any cell which 

 will still hold together will well repay treatment by this 

 method. 



