December 8, 192 1] 



NATURE 



479 



with full data. There are two Staffordshire examples 

 of Leucodonta bicoloria, and one of the two authen- 

 ticated British examples of Byrophila algae is in this 

 collection. In a brief article on the growth of the 

 Manchester Museum Mr. T. A. Coward points out 

 that that institution is now exceptionally rich in valu- 

 able collections ; in fact, few provincial museums can 

 vie with it in this respect. The famous Dresser 

 collection of birds and eggs and the valuable ornitho- 

 logical library attached thereto are almost indispens- 

 able to serious students. In the botanical department 

 of the museum are located the huge herbaria of Dr. 

 Cosmo Melville and Mr. Charles Bailey, along with 

 the Barker and other crj'ptogamic collections. 



The annual report of the Meteorological Office for 

 the year ended March 31, 192 1, has been submitted 

 to the Air Council for the first time since the control 

 has been taken over from the LorJs Commissioners of 

 His Majesty's Treasury. The period dealt with was 

 a time of transition and reorganisation, an important 

 change being the retirement of Sir Napier Shaw from 

 the directorship after twenty years' service and the 

 appointment of Dr. G. C. Simpson to the vacant posi- 

 tion. Among the many changes made in the carrying 

 on and extension of the work at its different centres 

 of activity a considerable increase has been made in 

 the staff employed. At the commencement of the 

 year the clerical, technical, and unclassified posts 

 numbered 182, and at the end of the year 213, leaving 

 65 vacancies to be filled to bring the staff to its required 

 strength. There is a restriction that candidates must 

 be drawn from ex-Service men. The Marine Division 

 of the Office deals with the issue of meteorological and 

 ocean-current charts, together with other weather in- 

 formation for the sailor. The Forecast Service, in 

 addition to publishing the Daily Weather Report, is 

 taking advantage of every opportunity to improve the 

 value of the daily weather forecasts and harvest fore- 

 casts, a spell notification being issued for the latter 

 when conditions are favourable for two or three days 

 of fair weather. Climatological observations are issued 

 in the Weekly Weather Report and in the Monthly 

 Weather Report. The meteorology of the whole globe 

 is also now regularly discussed. The British Rainfall 

 Organization is being controlled by the Meteorological 

 Office, and the publication of rainfall statistics for the 

 British Isles occupies much time. Observations on the 

 upper air also involve a large amount of work. 



The Faraday Society has issued as a separate 

 pamphlet of 83 pages an account of the discussion on 

 electro-deposition and electro-plating which took place 

 at the joint meeting of the society and the Sheffield 

 Section of the Institute of Metals in November, 1920. 

 Of the recent improvements referred to in the papers 

 read and the discussion which ensued, one of the 

 most important is the electro-deposition of the water- 

 jackets of aeroplane engines and the possibility opened 

 out by this success of building up elaborate parts of 

 machinery by the same process. The advantages of 

 cobalt-plating have been recognised for twenty years, 

 but it is pointed out that there is still difficultv in 

 securing the perfect adhesion of thick deposits. The 

 NO. 2719, VOL. 108] 



influence of colloids in the depositing tank on the 

 properties of the deposit is still imperfectly under- 

 stood, although it seems undoubted that their presence 

 leads to a decrease in the size of grain deposited. 

 The chairman and .one of the speakers expressed 

 regret that some of the authors of papers had not 

 made themselves acquainted with the work of previous 

 investigators before commencing their own experi- 

 ments. 



Ix the Chemical Neivs of October 28 Prof. B. 

 Brauner, of Prague, discusses the official report of the 

 International Commission on Chemical Elements 

 (Nature, August 18, p. 787). He cannot accept the 

 principle that " exact atomic weights are now becom- 

 ing factors of an analytical calculation rather than 

 features of a chemical hypothesis. " Prof. Brauner 

 has also the support of another authority on atomic 

 weight determinations, Sir Edward Thorpe, who in 

 his presidential address to the British Association at 

 Edinburgh, considered it of importance to "determine 

 with the highest attainable accuracy the departures 

 from the whole number rule." Prof Brauner raises 

 the following questions: "Why do we find with our 

 chemical processes and the balance that the atomic 

 weights of the pure elements, C, N, P, S, are larger 

 than their atomic masses [as found by the positive- 

 ray method]; why those of As, I, and Cs are smaller, 

 and why those of He, O, F, Na, are exactly equal 

 to their atomic masses, or in other words, why is 

 the hypothesis of Prout in its modern form valid for 

 atomic masses, but only in four out of twelve cases 

 for the corresponding atomic weights? Another in- 

 teresting question arises : Why are Aston 's isotopes, 

 as far as we know, always mixed up in the same pro- 

 portion? " In the Philosophical Magazine for October 

 Sir E, Rutherford gives reasons for the value, 14-01 

 (adopted by chemists) rather than 1400, found by the 

 positive-ray method, and suggests that a refinement 

 of the latter method might distinguish between the 

 two values. 



We have received from Messrs. Kodak a forty-eight- 

 page booklet, entitled "X-Rays," which they are dis- 

 tributing to the members of the medical profession. 

 It explains in a clear way the funamental laws of 

 practical importance that underlie the production and 

 use of X-rays, giving, for example, the relationship 

 between the length of the spark gap and the required 

 exposure, and the quality of the negative. The de- 

 velopment and other treatment of the exposed plate 

 or film is dealt with at length. The special aim of 

 the booklet is the standardisation of procedure, so 

 that the uniformity of method shall simplify 

 diagnosis. 



Sin'ce the introduction of the steam turbine the 

 question of the production of high-speed gear-wheels 

 has occupied the attention of many engineers. 

 Generally, the type of gear-wheels employed has been 

 double-helical. In a paper read by Eng.-Lt.-Comdr. 

 L. J. le Mesurier on November 22 before the 

 North-East Coast Institution of Engineers and 

 Shipbuilders, the Maag gearing is described and 



