April 9, 1908] 



NA TURE 



54; 



Is Concrete and Conslnictional Engineering for March 

 Colonel J. Winn summarises recent progress in the develop- 

 ment of reinforced concrete in Great Britain. During- the 

 past year steady advance* has been made, and the decision 

 to build the new General Post Office extensions and various 

 small post offices of reinforced concrete will have a far- 

 reaching effect. Another interesting article in the same 

 issue, by Mr. W. R. Crane, deals with the use of concrete 

 and reinforced concrete in mines. Details are given of 

 concrete linings at several shafts in the United States. 

 Other articles dealing with reinforced concrete in reservoir, 

 aqueduct, and conduit construction, with a ten-storey re- 

 inforced concrete building in Pittsburg, with reinforced 

 concrete bridges in Italy, sea defences in Holland, and 

 leading jetty on the Manchester Ship Canal, illustrate in 

 a striking manner the variety and number of the structures 

 which are being executed in this material. 



Two interesting papers were read before the Institution 

 of Engineers and Shipbuilders in Scotland on March 17. 

 Mr. H. A. Mavor discussed the electric propulsion of 

 ships, giving a comparison of the results to be obtained 

 on a ship of large size driven direct by steam turbines 

 with what can be done by the application of electric gear. 

 The ship, details of which are worked out, had a total of 

 17,000 horse-power delivered to the three propellers, and a 

 speed of 2o| knots. The propellers were 8 feet I5 inches 

 in diameter, and the speed of revolution was 377 per 

 minute. The maximum probable efficiency of these pro- 

 pellers is calculated to be 62 per cent. An electric equip- 

 ment would, it is shown, permit of the use of propellers 

 of about 14 feet diameter at 140 revolutions per minute, 

 and an efficiency not less than 70 per cent. — an improve- 

 ment more than sufficient to cover the loss in the electric 

 motors. In the second paper Mr. W. H. Hatfield traced 

 the evolution of malleable cast iron, and discussed its 

 present position in the metallurgical world. He takes 

 exception to the statement made in the report on the 

 nomenclature of iron and steel that malleable cast iron 

 should not be regarded as a variety of cast iron, inasmuch 

 as it does not exhibit the extreme brittleness that 

 characterises cast iron. He considers that it should 

 properly be classed as cast iron. The nomenclature is, 

 however, a matter of slight moment. The tests given by 

 the author show that malleable cast iron can be produced 

 giving a tensile strength of twenty-three tons per square 

 inch with an elongation of 19 per cent., a reduction of 

 area of 20'6 per cent., and a bending angle of 180°, results 

 which are as good as those given by many samples of 

 wrought iron. In structure, these castings are very similar 

 to wrought iron. 



In a note reprinted from the Atti of the Venetian Institu- 

 tion (Venice : C. Ferrari, 1908), Dr. U. Cisotti applies 

 elliptic functions to the problem of efflux of a liquid from 

 an opening containing an internal mouthpiece, a particular 

 case of two-dimensional discontinuous motion. The paper 

 forms the sequel to one in the Rendiconti del Circolo 

 matematico di Palermo, .xxv. (1908), on discontinuous 

 motion in general. 



The recently established Italian bi-monthly Scienza 

 pralica contains a paper by Mr. Lorenzo d'Adda on the 

 substitution of cement for steel in the armour of battle- 

 ships. The idea was suggested to the writer by the way 

 the Russian shells bounded ofT the batteries of the Japanese 

 in the siege of Port Arthur without producing any great 

 damage. Among the advantages suggested are a consider- 

 able saving of weight and cost ; moreover, the author points 

 out that efficient adhesion can be secured between the cement 

 NO. 2006, VOL. 77I 



and iron owing to the similarity of their coefficients of 

 expansion. Other papers "are an illustrated obituary notice 

 of the late Emilio Rossetti, late professor of physics at 

 Buenos Ayres, who was also a pioneer of engineering in 

 the Argentine Republic, and papers on the steam turbine 

 and the trans-Apennine canal. A considerable collection 

 of science abstracts, mainly dealing with engineering, is 

 another important feature of the new journal. 



Prof. Gruner, of Bern, has written a small pamphlet 

 dealing with " The World of the Infinitely Small " at the 

 instance of the Keplerbund of Godesberg, a society which 

 aims at the spreading of a knowledge of science amongst 

 the people. The author has succeeded in presenting his 

 subject in a most fascinating manner. He approaches the 

 infinitely small by a series of steps, one of which deals 

 with ultra-microscopic vision, and may be mentioned as 

 illustrating the author's method. The colour of ruby glass 

 is due, he shows, to the presence in it of minute particles 

 of gold too small to be seen with a microscope, under 

 which the glass looks a uniform material. When, how- 

 ever, the glass is examined by the ultra-microscope the gold 

 particles appear as points of light on a dark background 

 like stars in the sky. What, he asks, would be the appear- 

 ance of these particles if we could bring to bear on them 

 a power which exceeded that of the ultra-microscope as 

 much as the latter does that of the ordinary microscope ? 



The December (1907) number of Terrestrial Magnetism 

 and Atmospheric Electricity contains an article by van 

 Everdingen on the life and work of the late Dr. M. 

 Snellen, director of the Royal Meteorological Institute of 

 Holland. It deals mainly with the scientific and organising 

 work of Dr. Snellen. Apart, however, from the character 

 and importance of the scientific work in which Dr. Snellen 

 was engaged, and which secured him many friends 

 throughout the scientific world, his perfect mastery of the 

 English tongue, his genial character, and his fund of 

 anecdote made him a most welcome visitor to these shores, 

 and increased the number of his admirers. We are glad 

 to add our tribute of respect to that of the Dutch Meteor- 

 ological Institute. 



In the Bulletin of the U.S. Bureau of Standards for 

 January, Messrs. W. A. Noyes and H. C. P. Weber give 

 an account of their re-determination of the atomic weight 

 of chlorine. The method consists in weighing the 

 hydrogen absorbed in palladium and the chlorine in the 

 form of potassium chloroplatinate. The hydrogen, on being 

 passed over the heated chloroplatinate, combines with the 

 chlorine to form hydrochloric acid, which is condensed 

 and weighed. The mean result is 35-457, silver being 

 107-88. These values differ slightly from the 35467 and 

 107-91 found recently by Prof. H. B. Dixon and Mr. E. C. 

 Edgar by the same method. 



.According to the February number of the Journal of 

 the Rontgen Society, the committee of the society, which 

 has under consideration the establishment of a standard 

 unit of radio-activity, has made an interim report in which 

 it recommends that i milligram of pure radium bromide 

 be regarded as the standard, and that the ionisation pro- 

 duced by the y rays from it, after passing through i centi- 

 metre of lead, be taken as a measure of the unit of radio- 

 activity. There are, however, certain difficulties in the 

 adoption of these suggestions which the committee has 

 still under consideration, and will deal with in a future 

 report. 



The Cambridge University Press has issued a fourth 

 edition of " Petrology for Students : an Introduction to the 



