September 23, 1909J 



NATURE 



0/ 



second group is found to be due to the action of wind, ' 

 and must have been formed at a time when tlie prevailing 

 winds of the region were east and north-east. It appears 

 independently that the formation did actually take place in 

 late Pleistocene times. 



The report of the Meteorological Committee for the year 

 ended March 31 presents several points of especial interest. 

 The various publications containing statistical results have 

 been grouped together under the title " British Meteor- 

 ological Year-book "; it appears strictly up to date, which 

 will be a great advantage with regard to the supply of 

 information to inquirers, the number of whom have much 

 increased in recent years. Several publications on interest- 

 ing subjects are in course of preparation. The 7h. a.m. 

 international service of telegraphic weather reports, which 

 was brought into operation on July i, 1908, has been found 

 to work satisfactorily, and since the commencement of 

 the present year the reports by radio-telegraphy hitherto 

 received from H.M. ships have been supplemented by 

 wireless telegrams from .Atlantic liners. The observations 

 and accuracy of transmission have been satisfactory, but 

 only a small number of the messages were received in time 

 for current use, and much remains to be done before they 

 can be utilised in a day map of the ocean. The weather 

 forecasts issued in the morning newspapers and those issued 

 during the harvest season (June-September) have been very 

 successful, the percentage of accuracy (complete and 

 partial) amounting to 92 and 96 respectively. The com- 

 mittee contemplates making some important modifications 

 in the practice of the office as regards marine observa- 

 tions. Instead of devoting attention almost exclusively to 

 the compilation of average results, it is proposed to com- 

 pare the current with the mean values. Monthly outline 

 charts in suitable form, with the mean values of various 

 elements, are being prepared as the ground-work for 

 plotting the observations recorded on voyages. By this 

 means it is hoped eventually to trace the meteorological 

 relationships of changes in different parts of the world. 



The Physikalische Zeitschrift for September i contains 

 a long illustrated article by Dr. Max Ikl6 on old and 

 new little-known auxiliary apparatus for use in physical 

 and chemical laboratories. The pieces of apparatus men- 

 tioned are taken from the catalogues of nineteen German 

 firms of instrument makers, and are well worthy of the 

 attention of instrument makers in general. Of special 

 interest are the funnel holder of bent wire, the small 

 instrument stand of adjustable height, the metal lens 

 holder of the Schuster and Lees type, the Bunsen burner 

 with the gas inlet at the side so as not to be stopped up 

 by fused salts falling down the tube, the " emaille " in- 

 sulated connecting wire for electrical work, and, finally, 

 the list of monographs dealing with cements for physical 

 and chemical work. 



The well-known paradox of twisting a strip of paper 

 and joining its ends in such a way as to form a surface 

 with only one face and only one edge gives rise to the 

 cubic surface known as Mobius's surface. This is, in fact, 

 a surface generated by a straight line which revolves 

 about a point in its plane through an angle of 180°, while 

 the plane revolves about a straight line in itself through 

 360°. A discussion of the properties of this surface, by 

 Prof. C. E. Cullis, forms one of the papers in the first 

 number of the new Bulletin of the Calcutta Mathematical 

 Society. 



The Calcutta Mathematical Society has commenced the 

 issue of a Bulletin which promises to be an important 

 addition to our mathematical periodicals. In addition 

 NO. 2082, VOL. 81] 



to original papers it contains a " summary of prin- 

 cipal mathematical journals," with abstracts of many 

 papers; a section headed " Societies and Academies," with 

 full list of titles of papers read; "Reviews"; "Notes 

 and News"; a bibliography of "New Publications," 

 together with proceedings of the society itself, and lists 

 of members and of books in the society's library. While 

 the new bulletin thus assumes the cosmopolitan character 

 of its American contemporary, several of the features which 

 characterise it are distinctly new. The journal should fill 

 a want which is felt no less by English than by Indian 

 mathematicians. We had almost forgotten to mention 

 another commendable feature — there are no " problems and 

 solutions." 



A PAPER on the liquefaction of clay by alkalis and the 

 use of fluid clay casting in the ceramic industry, by Dr. 

 E. Weber, which formed the subject of an interesting 

 demonstration at the International Congress of Applied 

 Chemistry, appears in full in German and in English in 

 the eighth volume of the Transactions of the English 

 Ceramic Society, before which society the paper had 

 previously been read. The author shows that by the 

 addition of a suitable quantity of alkali a stiff clay, con- 

 taining not more than a normal quantity (15 to 20 per 

 cent.) of water, can be made quite fluid ; on pouring into 

 plaster moulds the water and alkali are drawn out, and 

 the clay quickly sets. The addition of the alkali does 

 not affect the properties of the finished material, provided 

 that it is only used in moderation, and the use of plaster 

 moulds tends still further to neutralise its effects. In 

 addition to the saving of labour-charges, it is claimed for 

 the casting process that, by completely disintegrating the 

 clay, it gives a very dense and uniform product free from 

 all defects, and that when porous materials are admixed 

 with the clay these become thoroughly impregnated, giving 

 an absolutely dense, homogeneous, and strong mass. The 

 method is in use on a considerable scale for the manu- 

 facture of glass furnaces, muffles for zinc distillation, gas 

 retorts, and sanitary goods, as well as smaller articles. 

 The same volume contains a description of a new cast- 

 ing machine, by J. G. Roberts, which is claimed to work 

 with less manual labour than those previously in use, 

 and to have an output of forty-five dozen articles per 

 hour. The society is to be congratulated on the initiation 

 of a series of abstracts from pottery journals, of which 

 a first instalment, covering forty pages, and dealing with 

 twenty journals, is now published. 



The Parseval airship has recently passed the stipulated 

 tests, and has been accepted by the Prussian War Office. 

 The conditions laid down were capability of remaining 

 at a height of about 5000 feet for more than ten hours, 

 of landing at any specified place, and, in addition, 

 capability of being quickly taken to pieces, transported 

 by rail or by two-horse vehicles, fi.xed up, filled again, and 

 started from any place. At the trials the airship actually 

 kept afloat for 11 i hours. We learn from a description 

 in Engineering for September 10 that the ship has a cigar- 

 shaped body about 190 feet long, and has a maximum 

 diameter of about 31 feet. The balloon is charged with 

 hydrogen, and has sufficient rigidity imparted to it by a 

 slight excess of gas pressure — 08 inch of water. To pro- 

 duce and maintain this gas pressure two hallonets or air- 

 sacks have been provided within the balloon ; these are 

 charged with compressed air at a pressure of about i^ inch 

 of water, and this supply is controlled by means of a 

 system of valves. The motor develops from 100 horse- 

 power to 120 horse-power, and the petrol tank contains 

 nearly 100 gallons. 



