February 4, 1909] 



NA TURE 



409 



Abyssinian rains and the Nile flood is the investigation of 

 the upper air in the monsoon region of the Sudan, whereby 

 tlie velocity and direction of the air currents at different 

 levels may be determined. The results of observations 

 hitherto made by means of pilot balloons are now being 

 prepared for publication, and will probably show in what 

 direction further efforts should be made. The problem 

 " concerns not Egypt alone, but all countries which depend 

 upon the rainfall of the monsoon winds which flow from 

 I lie Indian Ocean." 



The Humber Conservancy has recently been making 

 experiments with a buoy for lighting the channel of the 

 river in place of the gas buoys or vessels now in use. 

 This buoy has been placed at the disposal of the Con- 

 servancy by the International Marine Signal Company. 

 It consists of a generator tube containing carbide, which 

 is floated in a flotation chamber 8 feet in diameter. The 

 gas is generated by the water entering the lower end of 

 the generator and attacking the carbide. This causes a 

 slight gas pressure, which forces the water away from 

 the carbide, stopping the further generation until the 

 gas is used in the lantern, when the water rises again 

 and more gas is made. There is no moving mechanism 

 in the buoy, which draws about 9 feet ; the focal plane is 

 q feet above water-level. The light is of 340 candle-power, 

 and can be seen at a distance of more than a mile. It 

 shows a flash of abou' five seconds, and a dark period of 

 four seconds. 



Ok the many screen-plate processes of colour photo- 

 graphy on a single plate that have been proposed and 

 worked at since the Lumiire firm, of Lj-ons, produced their 

 autochrome plate, a very short time ago there was only 

 one, the " Thames " plate, that had reached the com- 

 nuTcial stage. We learn from the 7'imes that another, 

 the " Omnicolore " of Messrs. Jougia, is now on the 

 French market. We believe that this plate has compound 

 lines, alternating green and red, separated from each other 

 by narrower violet lines. By the use of transparent 

 colours, much more light may be transmitted than in the 

 case of the starch-grain screen of the autochrome plate, 

 with a corresponding gain in brilliancy and shortness of 

 exposure. The new plate has aroused much attention on 

 the Continent, and experimentalists in this country are 

 looking forward to its introduction here. 



The December (iqoS) number of Ion, a Journal of 

 Elcclronics, Atomistics, lonology, Radio-activity, and 

 Raumchemistry, contains six articles and reviews of seven 

 books. The whole of the articles, of which two deal with 

 applications of the electron theory to the properties of the 

 I'lements, appear to have been translated from the German 

 by persons unacquainted with the English scientific equi- 

 valent of many common expressions. Thus we read about 

 ■■ balls of electricity," " a negative charge unit," 

 "spherical plane," " Peltiere- " and " Halle-efl'ects," 

 " eutechticum," &c. Print and paper are good, and the 

 diagrams show a great improvement on those in the 

 November number. 



In the December (igoS) number of the Physical Rcvieiv 

 I here is an abstract of a paper communicated by Mr. 

 W. P. Boynton to the New York meeting of the American 

 Physical .Society in October, on the specific heats of gases. 

 In it the author emphasises the following as a more 

 rational method of treating the subject than is to be found 

 in the standard text-books. If the specific heat of a gas 

 al constant volume be multiplied by the molecular weight 

 we get a quantity we may call the molecular heat. The 

 fraction of this which is due to the translational motion 

 NO. 2049, VOL. 79I 



of the molecule is equal to 3/2-{7— i), where y is the ratio 

 of the two specific heats of the gas. The product of the 

 molecular heat by this fraction may be called the " trans- 

 lational molecular energy," and ought, according to the 

 kinetic theory of gases, to be a constant for all gases. 

 For forty monatomic and polyatomic gases and vapours 

 considered by Mr. Boynton, it differs from 3 by less than 

 3 per cent, in forty-five cases. 



Messrs. Townson and Mercer have sent us their new 

 double condenser. We have tried this apparatus, and find 

 it a very efficient condenser. It has two double tubes in- 

 side the condensing cylinder. The vapour to be condensed 

 is split up into two streams, and passes through two 

 narrow tubes, consequently there is very efficient cooling. 

 The apparatus contains two of these tubes, with two 

 separate inlets and outlets, consequently two distillations 

 can be carried out at the same time with one piece of 

 apparatus. Also two reflux operations can be conducted 

 at the same time. This, however, can only be done if 

 the flasks are of very small size, because otherwise the 

 necks will be too far apart for the tubes to fit in. As a 

 double condenser for distilling two products at once the 

 apparatus is fairly convenient ; but for carrying out two 

 reflux operations at once it is not of great use, first, because 

 the flasks must be small, and, secondly, owing to the 

 rigidity of the apparatus. The condenser was designed 

 by Mr. W. H. Rawles. 



Bulletin No. 68 of the New Mexico College of Agri- 

 culture contains a well-illustrated account of the injurious 

 insects commonly occurring in the region served by the 

 college, with methods for destroying them and for protect- 

 ing crops against their attack. The instructions are clear 

 and to the point ; the bulletin affords a very good example 

 of the work done for farmers by the .American colleges. 



The current number of the Journal of Economic Biology 

 contains an account, by Mr. Graham, of certain hitherto 

 undescribed insect pests affecting cocoa in West Africa. 

 One damages the trees by perforating the bark, and so 

 produces " gumming." Another burrows between the bark 

 and the wood of the branches, arresting the flow of the 

 sap ; it has caused a great amount of damage in cocoa 

 plantations of South Ashanti. The cultivation of cocoa 

 has only recently been introduced in this district ; the 

 weevil seems originally to have infested the indigenous 

 Papaw tree. 



The first number of a new monthly technical magazine 

 has appeared under the title Leather: Technical and Prac- 

 tical. It appeals specially to all workers engaged in the 

 leather industries, is edited by Mr. M. C. Lamb, and 

 published by the heather Trades Publishing Co., 143 

 Holborn Bars, London, E.C. The dependence of technical 

 processes upon the principles of science is recognised fully, 

 as the titles of some of the articles sufficiently show. 

 Prof. H. R. Procter writes on some unsolved problems in 

 leather chemistry, Mr. S. A. Gaunt gives an account of 

 chrome liquors and their application, and Mr. J. L. van 

 Gijn provides notes on liming of hides for sole leather. 



Parts iii. and iv. of vol. xi., and part i. of vol. xii., of 

 " The Proceedings and Transactions of the Nova Scotian 

 Institute of Science, Halifax, Nova Scotia," have been 

 received. The three books deal respectively with the 

 sessions 1904-5, 1905-6, and 1906-7, but have only just 

 reached us. Containing as the books do full and original 

 papers on the geology, botany, and zoology of Nova Scotia 

 by local observers, in addition to researches in chemistry 

 and physics conducted at Dalhousie University, Halifax, 



