272 



NATURE 



\yan. 22, i J 



their taste and genius, as well as on the aptitude and 

 natural vocal gifts of their pupils, depend in the greatest 

 measure the success obtained and the perfection of the 

 result. But whatever methods be adopted, the base of 

 operations is vital organisation and action, of which the 

 true apprehension and normal guidance must lead most 

 directly and certainly to the desired end." 



This, we take it, is the great aim, and the most useful 

 tendency of the book, namely, in the first place to make 

 known to those who desire to excel, either in singing or 

 in elocution, that something more is necessary than they 

 can obtain by the mere light of nature ; and secondly, to 

 enunciate the important truth that the art of using the 

 voice to the best advantage can only be effectively taught 

 by the aid of a competent knowledge of the nature and 

 capabilities of the natural organ — matters of which great 

 numbers of those who profess to teach have absolutely no 

 idea at all. The value, therefore, of such information as 

 is conveyed in this work, both to teachers and learners, 

 can scarcely be overrated. It is not possible here to 

 enter into details ; suffice it to say that the chapter treats 

 fully of vocal force, timbre, compass, and execution ; of 

 the modes of development; of the management of respira- 

 tion ; of the vibrating elements, the resonance apparatus, 

 and the articulation ; and it adds some useful data as to 

 the treatment of that troublesome vocal defect — stam- 

 mering. 



The last chapter is devoted to a subject of vital interest 

 to those who have to make public use of the voice, namely, 

 vocal hygiene. The maintenance of the vocal powers is 

 a matter of no less importance than their cultivation ; 

 but there is much ignorance and misunderstanding on 

 this point, and the advice the author gives, coming as it 

 does from one having authority, is most valuable. 



William Pole 



THE COPPER-TIN ALLOYS 

 •niriary Investigation of ihc Properties of the Copper- 

 Tin Alloys. A Report, Edited by Prof. R. H. Thurston, 

 of a Committee on Metallic Alloys, Presented to the 

 United Slates Board (Washington : Published at the 

 Government Printing Office, 1879.) 



IT is not a little remarkable that the study of the 

 metallic alloys has been so generally neglected. 

 Alfred Riche observes that this may in part be due to 

 the fact that the characteristics upon which we rely in 

 ascertaining the constitution of bodies are usually inap- 

 plicable to alloys. It is difficult for instance to determine 

 with accuracy such physical constants as their melting 

 points, for in many cases molecular rearrangement takes 

 place when the alloys are heated, and, again, the properties 

 of alloys are often greatly altered by the presence of 

 impurities in such small quantities that it is impossible to 

 estimate them by the balance. 



Systematic efforts to clear up the obscurities with which 

 the structure and nature of alloys are surrounded have, 

 however, not been wanting. Thus, not to mention the 

 well-known experiments of Hatchett, published in 1803 

 in 1855 Calvert and Johnson communicated to the British 

 Association the results of a series of experiments, and 

 in 1862 this body requested the late Dr. Matthiessen 

 to continue his experiments on the chemical nature of 

 alloys, the result being a report which certainly modi 



fied the views concerning them that had to that time 

 prevailed. England then has certainly not been behind 

 other countries in actual advance- in metallurgical pro- 

 cesses, but it is nevertheless true, as was pointed out by 

 Abel in an address as president of the Chemical Section 

 of the British Association in 1877, that the comparative 

 ease with which triumphs may be won in the field of 

 organic research has led the younger chemists to under- 

 estimate the importance of rigorous analytical work by 

 which their science has been built up. 



With regard to France the researches of Lcvol and of 

 Alfred Riche will always hold a high place in scientific 

 history ; and in Germany there are many classical re- 

 searches, such as those of Karsten and of Wertheim. 



The volume before us affords abundant evidence that 

 the Americans are not unmindful of the importance of 

 metallurgical investigation. It appears that a committee, 

 consisting of Prof. Thurston and Messrs. L. A. Beardslee 

 and David Smith, was appointed in 1877 by the Govern- 

 ment of the United States, to "assume the charge of a 

 series of experiments on the characteristics of alloys,'' 

 and the first result of their labours is an octavo volume, 

 edited by Prof. Thurston, of nearly 600 pages, illustrated 

 with photographs of fractures, and plates of curves repre- 

 senting the various physical constants of the alloys of 

 copper and tin. The committee hope soon to present a 

 similar report on the alloys of copper and zinc, and a 

 third report on the triple alloys of copper, tin, and zinc 

 will follow. They state that " the whole field has now 

 been explored and the useful alloys are proved to occupy 

 but a limited portion of its great extent, and it has now 

 been shown that a comparatively narrow band, extending 

 from ordnance bronze on the one side of this triangular 

 territory to Muntz metal on the other, contains all the 

 best of the alloys that are generally useful." 



The necessary researches were conducted in the me- 

 chanical laboratory of the Stevens Institute of Technology, 

 and the committee trust that this preliminary work will 

 prove " to have been so satisfactorily done that its repe- 

 tition may never be required, and that in future attention 

 may be confined to matters of detail which have been 

 shown to be of most promise." The committee did not 

 seek to determine the character of chemically pure metal, 

 but endeavoured to ascertain the practical value of com- 

 mercial metals, melted in the way that is usual in the 

 preparation of alloys in the foundry. The purest metals 

 that could be obtained in commerce appear, however, to 

 have been selected, the greatest care being taken to 

 ascertain by a minute analysis the amounts of impurities 

 in the metals employed and the composition of the 

 twenty-seven alloys forming the subject of the Report. 



After carefully noting the characteristics as to fracture, 

 colour, and hardness of each alloy, their resistance to 

 transverse stress was examined. Tests by tensile stress 

 then follow, and the results agree, in general, very closely 

 with those given by transverse stress. The alloys were 

 then submitted to torsional stress in a machine devised 

 by Prof. Thurston, and, if the autographic strain-diagrams 

 given by the machine are compared with the curves 

 representing resistance to transverse and tensile stress, a 

 marked similarity will be evident. Experiments proved 

 that the maximum resistance to compression is given by 

 the alloy containing 69'84 per cent, of copper, and the 



