i6 



NA TURE 



[May 2, 1907 



and the results of his explorations have been rommunicated 

 to the Soci^t^ d 'Encouragement (Bulletin, vol. cix., No. 3) 

 by Mr. K. Carnot. No trace of coal was found, but an 

 extensive Carboniferous area was traversed between Figuig 

 and In Salah, and it is possible that coal exists concealed 

 beneath the vast Cretaceous plateaux. 



At the meeting of the Institution of Civil Engineers 

 on April 16, papers were read on the Pyrmont bridge, 

 Sydney, New South Wales, by Mr. P. Allen, and on the 

 swing bridge over the river Avon at Bristol, by Mr. 

 \V. H. B. Savlle. The Pyrmont bridge across Darling 

 Harbour is 12 10 feet long. There are three 30-feet open- 

 ings in the Sydney approach for vehicular trafific to 

 wharves, while on the Pyrmont side the Darling Island 

 railway passes under a steel bridge of 25-feet span. 

 Electric motive power is used for working the swing span 

 and for roadway gates and for lighting, the whole being 

 operated by one man from a conning tower in the centre 

 of the swing span. The Bristol bridge, which is 600 feet 

 long, carries a carriage road and a double line of the 

 Great Western Railway. The main feature is the swing 

 span, which is 202 feet 6 inches long, pivoted on a pier in 

 the river. 



The current issue of the Transactions of the English 

 Ceramic Society (vol. vi., part i.) shows that much useful 

 work in the discussion of subjects relating to the clay- 

 working industries is being done by the society, which 

 meets at Tunslall, Staffordshire. The contents comprise 

 seven original memoirs, four of which are written by Dr. 

 J. W. Mellor, the hon. secretary of the society, and deal 

 respectively with the determination of the amount of 

 soluble salts in clays, excess air in firing kilns, the 

 sulphuring and feathering of glazes, and the influence of 

 high temperatures on porcelain pyrometer tubes. In the 

 other papers, Mr. W. Burton reviews the different methods 

 of recording high temperatures, Mr. W. F. Murray dis- 

 cusses the pottery oven of the future, predicting that gas 

 firing, at present unknown in the earthenware trade, will 

 fifty years hence be universal, and Dr. F. Shufflebotham 

 deals with the hygienic aspect of the pottery industry. 



The Bureau of Science of the Government of the 

 Philippine Islands publishes the Philippine Journal of 

 Science in three sections, dealing with : — A, general 

 science ; B, medical science ; and C, botany. The numbers 

 in each section appear as rapidly as material is available, 

 and the latest number to hand (A, vol. ii.. No. i) shows 

 that the papers attain a high standard of excellence. 

 There are four original memoirs, on the terpene oils of 

 Manila elemi, by Mr. A. M. Clover; on the action of 

 sodium on acetone, by Mr. R. F. Bacon and Dr. P. C. 

 Freer ; on a new subspecies of Philippine Cicindelidse, by 

 Mr. W. Horn ; and on the proximate analysis of Philip- 

 pine coals, by Mr. A. J. Cox. In the last-mentioned paper 

 the author shows that the directions for coal analyses 

 recommended by the American Chemical Society are in- 

 applicable to certain Philippine coals. These coals are 

 easily detected by the shower of incandescent carbon 

 particles which are driven off when the sample is subjected 

 to rapid heating. This mechanical loss can be overcome 

 by expelling the volatile matter very slowly so that the 

 escaping gases do not ignite. This smoking-off method 

 approaches the conditions existing in a coke-oven. 



An interesting account of the Blue Grotto at Capri has 

 been published by Mr. F. Furchheim, of Vienna, 2 Seiler- 

 statte, District I., for private circulation. It is reprinted 

 NO. 1957, VOL. 76] 



from the Deutsche Riiiulschan fiir Geographic und 

 Statistik (January), and deals with the changes which 

 have taken place in the grotto, considered particularly in 

 reference to variations of sea-level, from the times of the 

 ancients down to the present day, as revealed by historic 

 documents and references. 



The Revue scientifique (April 13) publishes an interest- 

 ing account of graphic methods of calculation in the form 

 of an inaugural address by Prof. Maurice d'Ocagne. As 

 is well known, Prof. d'Ocagne introduced the method of 

 ** nomography," in which calculations arc performed by 

 drawing lines across a diagram with a ruler. His use of 

 the method for solving algebraic equations is well known. 

 That a piece of squared paper forms an excellent substi- 

 tute for a slide rule when used in this way is so simple 

 and obvious that it is surprising how often the fact is 

 ovei'looked. 



The relations of sciencr to questions of national interest 

 forms the subject of a number of the papers in the current 

 issue of Science Progress. Mr. James Johnstone discusses 

 the international fishery investigations, and directs atten- 

 tion to the unsatisfactory position of fishery statistics, par- 

 ticularly in connection with Great Britain. The relation- 

 ship of mining to science, in the hands of Mr. W. E. 

 Lishman, forms the basis for further reflections on 

 England's neglect of science. Dr. John Wade replies to 

 Prof. H. E. Armstrong's attacks on our present medical 

 curriculum ; and Prof. Armstrong contributes an address on 

 "The Opportunity of the Agriculturist," and draws a 

 timely moral from the eflRciency of the United States 

 Agricultural Bureau. Mr. R. H. Biflen also shows thf 

 need of agricultural research in his paper on modern 

 plant-breeding methods. Mr. Shipley, in his paper on 

 the danger of flies, puts in one good word for the motor- 

 car, which, with all its faults, affords no nidus for flies. 



In a paper contributed to the Physical Review for 

 March, Mr. W. R. Turnbull discusses the forms and 

 stability of aeroplanes. The author describes laboratory 

 experiments made with planes and singly and doubly 

 curved surfaces, and draws curves showing the lift, 

 drift, and coordinate of the centre of pressure expressed 

 graphically in terms of the angle of inclination. He 

 rightly directs attention to the supreme importance of 

 longitudinal stability. This is a factor which is apt to 

 be neglected by practical aeronauts whose main thought 

 is to build flying machines in the hope of winning prizes. 

 The data in question will afford useful material so far 

 as they go, for studying the stability of various types. 

 This stability depends, however, on other factors also,, 

 such as the moment of inertia and the position of the 

 centre of gravity of the proposed apparatus. Another 

 interesting note was recently contributed to the Comptes 

 rendus by Captain Ferber, dealing with the forms of 

 propellers calculated to give the maximum efficiency. 



Mr. F. W. Aston writes in reply to Mr. A. A. Camp- 

 bell Swinton's letter, which appeared in Nature of 

 April 18 (p. 583), to say that when Mr. Swinton has the 

 opportunity of comparing the full text of the Royal Society 

 paper with his own results of 1898 he will recognise the 

 wide dissimilarity of conditions, effect, and explanation 

 between them. The mica mill referred to in the abstract 

 is designed to show that inside the dark space, under 

 conditions of moderate pressure and continuous current, 

 the mechanical energy flowing towards the kathode in the 

 path of the kathode rays is far jn excess of that flowing 



