July 9, 1908] 



NA TURE 



2\\ 



National Geographic Magazine under the title of " An 

 AiTierican Fable," Mr. Gifford Pinchot, chief of the United 

 States Forest Service, raises the question of the exhaustion 

 of the national resources, a subject which has recently 

 been discussed by President Roosevelt. The growth of the 

 forests at present is, he states, but one-third of the annual 

 consumption, and the timber will last only twenty years 

 at the existing rate of expenditure. For a country so 

 largely dependent on wood for building and fuel, the result 

 of tlie wasteful policy of the last half-century will be 

 disastrous, and Canada, the only available source of 

 supply, will soon need all her timber for her own use. 

 The anthracite coalfields, again, are said to be in danger 

 of exhaustion in fifty years, and the bituminous coal will 

 fail early in next century. Some of the older oilfields are 

 already worked out ; the natural gas has been wasted, 

 burning night and day in many townships. Iron deposits 

 grow less every year. The ranches in the west feed only 

 half the cattle which they would produce under intelligent 

 management, and the prices of meat are rapidly rising. 

 The present, he observes, is one of the most critical epochs 

 in the national history, and disaster is sure to occur unless 

 a policy of conserving these resources is enforced. The 

 only practical remedy, he suggests, for this dangerous state 

 of things is the appropriation of the vast supplies of water 

 power for the production of electrical energy to take the 

 place of coal for machinery, heating, and illumination. 

 If these fall into the hands of trusts the prospect is gloomy 

 in the extreme. " We are no more exempt from the 

 operation of natural laws than are the people of any other 

 part of the world." 



The new Bernese Alpine Tunnel and the Lotschbirg R.iil- 

 way are discussed in an article by Dr. C. Koppe in Himmel 

 und Erdc for April. In pointing out the hindrance caused 

 by the Bernese Alps to the utilisation of the Simplon 

 Tunnel route. Dr. Koppe emphasises the great commercial 

 advantages, not only to Bern and north-west Switzer- 

 land, but also to the western Rhine district, which would 

 follow the construction of a railway connecting Brieg, at 

 the northern end of the Simplon Tunnel, with Bern. The 

 first part of the line, from Spiez to Frutigen, has been 

 constructed for several years, and it has been decided to 

 continue this line to Brieg, a tunnel being pierced through 

 the Bernese .Alps at Lijtschberg. The building of the lines 

 from Brieg and Frutigen to the south and north of the 

 tunnel entrance will be commenced in the summer of 190S, 

 and the whole international railway, Bern, Lbtschberg, 

 Simplon, should be completed in five years. The Bernese 

 Alpine Railway Company was formed in July, 1906, and 

 the work of triangulation carried out in the autumn of the 

 same year, accurate data being obtained for fixing the 

 length ajid direction of the tunnel. The three mountains 

 situated on the line of the tunnel. First, Immenengrat, and 

 Wildelsiggrat, were used as bases for the survey. Boring 

 was commenced in the spring of 1907, electric power being 

 derived from works at Spiez and Gampel. Dr. Koppe 

 gives a detailed description of the proposed line from 

 Frutigen, through Mitholz and Kandersteg, to the tunnel 

 entrance, and also of the line from Goppenstein to Brieg, 

 noticing the numerous small tunnels and viaducts which 

 will be required. 



We learn from the Bulaivaya Chronicle that at a meeting 

 of the Rhodesian Scientific .lAssociation on May 19, the 

 Rev. Father E. Goelz, S.J., read a useful paper on the 

 rainfall of Southern Rhodesia, based on observations at 

 about fifty stations, reduced to the period 1888-1907. 

 Among the principal results we note that Mashonaland, as 

 XO. 20ig, VOL. 78] 



a whole, has an annual average of more than 30 inches; the 

 eastern range of high altitudes has 40 inches and upwards, 

 while on the slopes towards the Zambesi and Limpopo the 

 average is between 25 and 30 inches. Matabeleland is 

 much less favoured ; along the watershed the average is 

 25 east of Bulawayo and 20-25 west of that place. Between 

 .'\pril and October not more than an inch of rain falls on 

 an average in Rhodesia, west of the eastern range -of 

 high altitudes ; from October to March 90 to 98 per cent, 

 of the year's rainfall takes place. Reference must be made- 

 to the original paper for many very interesting details in 

 connection with the regime of the rainfall and the influence 

 of wind direction. With regard to the question of cycles 

 the author states that, although there are only ten years' 

 barometer observations available, his inquiries show that 

 investigation on the line of a 19-year variation in the 

 barometer and of a corresponding variation in the rainfall 

 might perhaps be continued with profit. 



Prof. Silvanus P. Thompson's " Kelvin Lecture," 

 delivered to the Institution of Electrical Engineers on 

 April 30, has been issued as a separate pamphlet by 

 Messrs. Spon. It consists of a sketch of the life and work 

 of Lord Kelvin, and gives within its short compass a more 

 vivid picture of the great master than have several more 

 lengthy accounts. 



The Sanitas Electrical Co., Ltd., of New Cavendish 

 Street, London, W., has sent us a profusely illustrated and 

 conveniently arranged catalogue, running to 338 pages, 

 dealing with electromedical .apparatus which the company 

 is prepared to supply. The catalogue provides remarkable 

 evidence of the numerous applications in medical and 

 surgical science of the Rontgen and other rays. Incident- 

 ally, the appliances described in the catalogue serve to 

 illustrate the debt of gratitude which mankind owes to 

 the men of science upon whose work, often little recognised, 

 these remedial measures are based. 



M. P. ViLL.iRD e.xhibited before the Socidt^ Francjaise de 

 Physique on May 4 an experiment in which the Aurora 

 Borealis was produced artificially (see N'ati're, September 5, 

 1907, vol. I.x.xvi., p. 4S1), and a complete description of the 

 method used is given by M. Villard in the June number 

 of the Journal de Physique. A large exhausted flask is 

 placed between the poles of an electromagnet, and a 

 stream of kathode rays is shot into the flask in a direction 

 oblique to the magnetic field. In these circumstances the 

 rays become a luminous spiral with its axis directed 

 towards one of the poles of the magnet. At a point near 

 this pole the path of the ray is nearly reversed, and the 

 spiral proceeds towards the other pole, at which the 

 reversal is repeated. Owing to the axes of the spirals 

 being slightly inclined to the lines of the field, they 

 generate a spheroidal surface coaxial with the field with' 

 a circular piece cut out at each pole. According to the 

 theory which this experiment at once suggests, in our 

 observation of the aurora we are looking at the edge of 

 one of these openings from underneath, the spirals coming 

 nearest to the earth's surface at these points and being 

 most luminous. 



Messrs. Leitz, of Wetzlar and London, have submitted 

 tor our inspection one of their prism binoculars of improved 

 design. Like the majority of modern instruments of this 

 type, these are constructed on the principle of Porro's 

 erecting prisms, but several additional patents on details 

 enable special points of excellence to be claimed. The 

 tubes are provided with focussing arrangements and inter- 



