388 



NATURE 



[JA 



to zero at 3° A. ; at thin temperature the renUtanre of 

 mercury \% Icsii than one ten-millionth of it<i value 

 nt 0°, whilst nt i-.^" A. it is still smaller : (4) inve«tigationH 

 of magnetic susceptibility and thermoelectric force. Atten- 

 tion may also be directed to two articles on the fixation of 

 atmospheric nitrogen in the same journal of November 30 



and December 15, 191 1; these are accompani' ' ' . rifs 



of interesting and unfamiliar illustrations. 



Tub first number of The Chemical World is a very 

 readable production. The new journal is a monthly 

 pericxiical published by Messrs. J. and .\. Churchill; its 

 aim is " to presmt to those interested in th*- many branches 

 of chemistry an account of progress in both theory and 

 practice." Written from this viewpoint, a number of 

 short articles deal with various topics of chemical interest, 

 and form the chief feature of the magazine. Among these 

 are "The Detection of Mydriatic Alkaloids," by Mr. F. H. 

 Carr, discussing a problem which arose recently in a 

 notable murder trial ; " The Chemical Characterisation cf 

 Soils," a useful contribution by Dr. E. J. Russell; "The 

 Recent Progress of Organic Chemistry," in which Dr. 

 A. Clayton describes Knorr's isolation of the ketone and 

 enol forms from ethyl aceto-acetate ; and a summary of 

 " Metallurgical Progress in 1911," by Mr. G. T. Hollo- 

 way, .^n illustrated article on the chemical department 

 of the Royal College of Science, with a portrait of Sir 

 Kdward Thorpe, is the first of a series of similar accounts 

 which will deal with the chemical establishments of 

 modern universities and technical colleges. Other serial 

 contributions commenced are one by Mr. E. Hatschek on 

 " The Physics and Chemistry of Colloids," and one on 

 " Chemical Research " by the editor. Sections are also 

 devoted to physical chemistry, chemical engineering, and 

 chemical industries, whilst patents and commercial matters 

 are not forgotten. Thus the new venture appeals to many 

 interests, and, judging by the first issue, it deserves a 

 cordial welcome. 



In a paper on the direct experimental determination of 

 the stresses in the steel and in the concrete of reinforced- 

 concrete columns, read before the Institution of Civil 

 Engineers on January 9 by Mr. W. C. Popplewell, is 

 described a method of measuring the simultaneous shorten- 

 ing of the steel bars and of the concrete. Martens extenso- 

 meters were used ; for the steel these were applied to the 

 ends of pairs of pins projecting from the reinforcing bars 

 through holes in the concrete ; for the concrete the cxtenso- 

 meters were applied to the surface as near as possible to 

 the steel. The elastic moduli for the steel and the concrete 

 were thus found to be 30,200,000 and 1,535,000 lb. per 

 square inch respectively. A further set of experiments 

 carried out to determine the intensity of the frictional grip 

 of the concrete on the steel . resulted in values ranging 

 from 300 to 600 lb. per square inch of bar surface, to 

 cause slipping. When all the effects of eccentric loading 

 have been eliminated from the results of the tests on 

 columns, there is no evidence to indicate that slipping took 

 place. In columns of this kind, made up with plain 

 smooth bars, the two materials behave like one, so far as 

 their strain effects are concerned. 



.An article on propeller erosion in Engineering for 

 January 12 gives an account of a research conducted bv 

 Dr. O. Silberrad, of Buckhurst Hill, Essex, in conjunction 

 with the Manganese Bronze and Brass Company, Ltd. 

 Propellers driven by comparatively slow-running recipro- 

 cating engines are free from erosion when constructed of 

 manganese bronze. When, however, the same alloy was 

 used for turbine-driven propellers erosion reappeared, and 

 NO. 2203, VOL. 88] 



often of a very M-riou<» character. 1. 



Mauretania and Lutilania, had no remedy been found th- 

 propellers would have required replacing every few rn'-"*' 

 at a cost of »om<* thousands of pounds. Each pr< 

 weighed about 30 tons, and the coKt rai^e* from i^ui. << 

 180/. per ton. The erosion wems to have been due to th- 

 futectic being washed away, the mixed crystals const i 

 tuting the main mass of the alloy being practically ur 

 affected. The research has been successful in the dis' 

 of an alloy which is now in actual service on the .^/ 

 tania, and has proved itself practically inerodible. 1 1 

 new alloy is patented conjointly by Mr. P. R. Parson-, 

 of the .Manganese Bronze and Brass Company, and Dr 

 Silberrad, and is called Parsons' New Turbadium. It hji- 

 a tensile strength of 38 to 40 tons per square inch, an 

 elastic limit of 18 to 19 tons per square inch, and an 

 elongation of 15 per cent, on 2 inches. In the erosion 

 tests it showed an endurance about five times that of 

 ordinary high-tension bronze, and this result has been 

 confirmed in actual service. We understand that xh- 

 British .Admiralty has approved its use for the proj.' 

 of war vessels fitted with turbine engines. 



The thirty-ninth issue of " Willing's Press Guide." that 

 for 1912, has, as usual, been carefully revised, and well 

 maintains its character as a handy and easily consulted 

 index to the Press of the United Kingdom and to th< 

 principal colonial and foreign periodicals. .A variety of 

 general information adds to the value of the volume. 



.A COPY of a convenient monthly weather chart for 

 daily observation has been received from Messrs. Georg'- 

 Philip and Son, Ltd. Provision is made for a record of 

 readings of the wet and d.-y-bulb thermometers, maximum 

 and minimum thermometers, rain-gauge, and barometer. 

 Space is also allotted to wind and weather observations. 

 The price of each sheet is one penny. 



\ NEW and enlarged edition of " Soap-bubbles : tiv '.v 

 Colours and the Forces which Mould them," by Prof. C. V. 

 Boys, F.R.S., has been published by the Society for Pro- 

 moting Christian Knowledge. The several new and 

 original sections which the present issue contains provid*", 

 like the lectures Prof. Boys has been giving lately to the 

 Royal Society of Arts juvenile audiences, still further 

 evidence of the author's genius for experimenting and his 

 talent for clear and interesting exposition. The pric- .f 

 the new edition is 35. 



Sir Edw.\rd Thorpe's well-known " Dictionary of 

 .Applied Chemistry " is being revised and enlarged, and 

 -Messrs. Longmans and Co. announce that the new edition 

 will be issued in five volumes. The first volume will be 

 ready in a few days, and vol. ii. early in the summer. It 

 is hoped that the work will be completed within two years. 

 Messrs. Longmans announce also that the work on 

 " Surgery," by Sir W. Watson Cheyne and Mr. F. F. 

 Burghard, has been entirel}' revised and rewritten with 

 the assistance of Mr. T. P. Legg and Mr. Arthur 

 Edmunds. The first volume will be issued before the end 

 of the present month, and vol. ii. in April next. 



OVR ASTRONOMICAL COLl'MX. 



Possible Changes in S.\tl'rn's Rings. — .At the meeting 

 of the Royal Astronomical Society, held on Friday last, it 

 was announced that a telegram had been received, by Sir 

 David Gill, from Prof. T<xld. in which he said : — " Near 

 the extremities of the major axes of the bright outer ring 

 of Saturn, with the aid of a powerful telescope, I have 



