February, 1915. 



KNOWLEDGE. 



53 



Dr. Dieterich (page 543) describes various mixtures of 

 alcohol with benzene, commercial acetone, and petroleum 

 oil as being suitable for motor engines, but points out that 

 in each case preliminary' heating of the carburettor and 

 reduction of the supply of air are necessary. 



Dr. Mohr (page 558) discusses the suitability of the various 

 mixtures suggested by Dr. Hempel and Dr. Dieterich. In 

 his experience only the simplest mixtures of alcohol with 

 hydrocarbons have given satisfactory results. Thus he 

 has found suitable for the purpose a mixture of alcohol and 

 benzene in equal parts ; or of alcohol, one half ; benzene, 

 a quarter ; and petrol, a quarter. Naphthalene is an 

 unsuitable ingredient owing to its forming crystalline 

 deposits. Attempts have been made to use alcohol con- 

 taining about one half per cent, of ammonium perchlorate, 

 but these were unfavourable owing to the chlorine 

 compounds formed in the explosion attacking the metal. 

 All three chemists express their confidence that Germany 

 will be able to produce sufficient alcohol for their motor 

 engines, and that all mechanical difficulties can be over- 

 come. They mention that about a dozen firms are now 

 manufacturing carburettors specially adapted for burning 

 alcohol and mixtures of alcohol and benzene. The addition 

 of a small amount of motor oil is suggested as a means of 

 preventing rusting of the tubes by the alcohol. 



PROPERTIES OF XAPHTHENIC ACIDS.— The waste 

 alkaline lyes from the refining of petroleum oils contain a 

 large proportion of compounds which are known as 

 " naphthenic acids." They can readily be separated by 

 treating the lyes with a mineral acid, and, owing to the in- 

 creasing scarcity of coconut and palm oils, are of grovring 

 importance for the manufacture of soaps, especially for such 

 as -irill give a lather \\ith salt water. Unfortunately, their 

 use in this direction is restricted by their unpleasant odour, 

 and attempts are being made in many directions to obviate 

 this drawback. 



In the last issue of Les Mati&res Grasses (1914, VII, 4115), 

 M. E. Schmitz gives an account of his systematic experiments 

 upon the deodorisation of the acids. He found that, by 

 repeatedly treating them \v'ith dilute sodium carbonate 

 solution, an insoluble compound of phenolic character, 

 which showed the characteristic odour in an intensified 

 degree, could be separated, while the final product had only 

 a very faint odour. The dark, insoluble " oil " gave an 

 intense bluish-green colour with copper salts, and could 

 be used as the basis of a lacquer for wood. Attempts to 

 deodorise the naphthenic acids by hj-drogen were unsuccess- 

 ful, but treatment with ozone for about tivo hours reduced 

 the odour to some extent, and could be used as a practical 

 process after removal of the evil-smelling phenolic sub- 

 stances by means of sodium carbonate as described. 



GEOGRAPHY. 



By A. Scott, M.A., B.Sc. 



MAPS AND PHYSICAL GEOGRAPHY.— In the 



Geographical Journal for January Mr. Alan Ogilvie discusses 

 the utihty of our available maps from the point of view of 

 the physical geographer, and makes a number of suggestions 

 regarding the ways in which they might be made more 

 useful. As it has not been found possible, so far, to combine 

 the virtues of the different editions of the Ordnance Survey 

 maps, all editions should be kept on sale. Similarly, atlases 

 of land-form types, on one-inch and six-inch scales, would 

 be of great service to teachers. The chief defect of geological 

 maps, from the geographer's point of view, is that it is often 

 impossible for the non-geologist to determine from such 

 maps the hthology of the district, and this can only be 

 remedied by the preparation of lithological maps. Other 

 things which might be indicated on these maps are the 

 porosity and comparative resistance of the various strata. 

 In the investigation of land forms, much useful information 

 could be obtained from maps showing what processes have 

 been most effective, and also the stage of maturity at which 



the various features have arrived. In connection with 

 water supply, it is suggested that not only might the 

 different types be cartographically indicated, but also the 

 variation of headwaters and river volumes. Other pheno- 

 mena which might lend themselves to more accurate map- 

 ping than they have hitherto received are meteorological 

 conditions, vegetation, and oceanographical and soil-survey 

 data. 



GEOGRAPHY AND STRATEGY.— There are two 

 principal ways in which geographical conditions affect 

 strategy : one with regard to lines of advance and the 

 other with regard to obstacles. The former are determined 

 by the occurrence of level country or of " defiles," such as 

 river valleys. According to Hilaire Belloc [Geographical 

 Journal, January, 1915), obstacles are of five types : rivers, 

 including canals, forests, hill countrj'. deserts, and marshes. 

 Rivers are never permanent obstacles, though they may have 

 a great tactical value temporarily, such as the Ourcq had 

 during von Kluck's retirement. Forests are serious obstacles 

 unless there are numerous defiles, an example in the present 

 war being the Forest of Argonne. HUls vary in importance, 

 and at one period those along the Aisne proved invaluable 

 to the German Army. As campaigns have seldom been 

 carried out in deserts, there are few data from which to 

 deduce the value of such country. IMarshes provide the 

 greatest obstacle of all, as it is practically impossible to 

 entrench in them. This has been well shown by the 

 campaign in the Yser district. 



GEOLOGY. 



By G. W. Tyrrell, A.R.C.Sc, F.G.S 



PERMO-CARBONIFEROUS BRECCIA OF ENGLISH 



INIIDLANDS. — The chief exposures of this deposit occur 

 near Birmingham. It consists of sandstones and marls, 

 with occasional sheets of very angular breccia, which is 

 formed of blocks of volcanic rocks, grits, slates, and 

 limestones identical with rocks from the Welsh border. 

 This puzzling deposit has been variously ascribed to volcanic, 

 glacial, or lacustrine agencies ; but H. T. Ferrar, in a paper 

 read before the British Association, Australia, 1914, shows 

 that it closely resembles certain desert formations. He 

 instances especially the material which partially fills the 

 wadis, or steep-sided gorges, of the folded mountain-chain 

 forming the watershed between the Nile and the Red Sea. 

 " The climate is arid, with occasional heavy thunderstorms, 

 causing temporary- currents, which sweep for%vard all rock 

 material loosened during the prevailing dry climate." 

 This material is very angular and fresh, and, in slipping 

 down the hillsides, or in course of violent water transport, 

 the blocks are frequently scratched, grooved, and even 

 shattered by mutual impact. Huge blocks may be carried 

 as much as a hundred miles down the wadi channels by 

 water, and hence it is not necessary to invoke the agency 

 of ice to explain the occurrence of large blocks in similar 

 deposits. The valley-fill of most wadis in the Eastern 

 Desert of Egj'pt is an unconsolidated breccia, so similar 

 to that of the Permo-Carboniferous in the English Midlands 

 that there can be little doubt that the tivo originated under 

 similar climatic conditions. 



METEOROLOGY. 



By \ViLLL\M Marriott, F.R.Met.Soc. 



THE WEATHER OF FEBRUARY.— February is the 

 last month of winter, and extremely variable in character. 

 There is an old proverb : 



" February fill dyke, be it black or be it white ; 

 But, if it be white, it 's the better to like," 



but more recent observations tend to set aside the old 

 proverb. In severe winters the frosts of the two previous 

 months continue, or return with great intensity ; while 

 on several occasions the greatest cold of the year has 

 occurred in this month. It was a very cold month in the 



