February 21, 1918] 



NATURE 



491 



motion of translation and rotation. The object of the 

 paper is to apply the method of periodic conformal 

 transformation to problems of this class of a more 

 general character than those commonly given in text- 

 books. For this purpose the motion is divided into two 

 portions, viz. a uniform rotation of the solid and liquid 

 and a spinning motion with equal and opposite spin 

 past the solid boundary supposed at rest, the two 

 motions combined making up the required hydro- 

 dynamical solution. 



In the December issue of The Central Mr. R. A. S. 

 .Thwaites, of Messrs. Allen and Co., Bedford, gives a 

 valuable summary of the results which have been ob- 

 tained by a study of the effects of the heat treatmenr 

 of nickel-chrome and other steels on their mechanical 

 properties. This study has been forced on the British 

 steel manufacturers by the authorities insisting that 

 steels for aeroplane engines should satisfy an impact 

 test which the foreign steels available before the war 

 satisfied without difficulty. By hardening the steel at 

 830° C, and tempering at 640° C. instead of 250° C, 

 the number of foot-pounds required to break a small 

 notched bar by the Izod test can be raised from 25 to 

 92. The yield point and ultimate strength of the steel 

 are reduced by this treatment, and Mr. Thwaites gives 

 furves showing how all the principal mechanical pro- 

 perties of the steel are affected by tempering at tem- 

 peratures between 350° and 600° C. From these curves 

 the proper tempering temperature to ensure steel of 

 given mechanical properties may be found. 



During the last few years a number of experi- 

 menters, including Reinganum, Walmsley and 

 Makower. Miehl, Mayer, Sahni, Kinoshita and Ikeuti, 

 have published excellent photographs showing the 

 tracks of individual a particles from radium which 

 strike the photographic plate at glancing incidence. 

 In a recent paper Kinoshita and Ikeuti (Journ. Coll. 

 Sci., Imper. Univ., Tokio, November 20, 1917) sum up 

 our information on this interesting subject, and show 

 a number of such photographs. Special methods were 

 used to obtain very small radiating nuclei, so that the 

 radial tracks of the expelled a particles show up clearly. 

 The track of an o particle (magnification 500 to 1500) 

 is not continuous, but marked by a number of de- 

 veloped grains from ten to twenty in number, depend- 

 ing on the velocity of the particle. An estimate is 

 given of the diameter of these grains, with a discussion 

 of the general theory of their formation and of the 

 action of a rays on a photographic plate. 



A RECENT issue of Industrial Management {The 

 Engineering Magazine) contains several informa- 

 tive articles by officials connected with depart- 

 ments of the United States Government. The 

 Hon, William C. Redfield, Secretary of the De- 

 partment of Commerce, gives several striking 

 instances of the waste that goes on continually in in- 

 dustry. According to the Department of Agriculture, 

 65 per cent, of a; tree is wasted in converting it into 

 lumber, and ten million dollars further is wasted 

 annually in drying the lumber so made. Again, vast 

 amounts of scrap wood available for making pulp, 

 alcohol, or vegetable products are burned or allowed to 

 rot. It has only recently been realised that whale meat 

 is a delicacy, and that the intestines of the whale 

 make good leather. In the past the carcasses of seals 

 were invariably thrown away after removing the skin, 

 although the blubber can be used to make oil, the flesh 

 for meat, and the bones for fertiliser. Germany, on 

 the other hand, is pre-eminently an economical coun- 

 try, and many of her industries, such as those asso- 

 ciated with dyestuffs and explosives, were built up on 

 NO. 2521, VOL. 100] 



so-called waste products. The four chief defects in 

 industry to be overcome are : — (i) Separation of science 

 from industry ; (2) industrial waste ; (3) lack of indus- 

 trial and commercial education ; and (4) ignorance of 

 manufacturing costs. The Hon. L. F. Post gives a 

 summary of the work of the Department of Labour 

 in connection with the war. Among other feats, it 

 has registered 10,000 ship workers in ten days, placed 

 more than 300,000 men in manufacturing employment 

 last year, and adjusted 323 labour controversies in war 

 industries between January i and October 25, 1917. 

 Finally, Mr. H. E. Coffin discusses the general qrgan- 

 isation of the business department of the United States 

 Government, and analyses the functions of the some- 

 what complex boards and committees. The complaint 

 has been made that there is too much subdivision. 

 Mr. Coffin, however, thinks that the confusion is more 

 apparent than real — in short, that the three main 

 groups of the war organisation, dealing respectively 

 with purchasing, industrial policy, and labour, are 

 " shaking down." 



Engineering for February 15 reproduces some in- 

 teresting photographs of damage done to the machinery 

 of German steamers interned in Brazil. These photo- 

 graphs illustrate the thoroughness of German destruc- 

 tion ; in one case of two damaged cylinders, at least 

 8000 holes must have been drilled transversely and 

 vertically through the cylinders. The cylinders illus- 

 trated had been broken into hundreds of small pieces, 

 and in order to make new cylinders to suit the set of 

 engines it was necessary to collect as many pieces as 

 possible and to patch them together so that the dimen- 

 sions could be measured accurately. Most of the 

 broken parts were found carefully stored between decks, 

 evidently in order to be used as scrap metal in G^r- 

 many in the event of the return of the ships to the 

 Fatherland. The number of German viessels interned 

 in Brazil was approximately forty-five, totalling 235,000 

 gross tons. In the early part of 1917 the Brazilian 

 Government invited Messrs. Vickers, Ltd., to survey 

 the damage and carry out the steps necessary for re- 

 pair. It was found that the repairs oould be carried 

 out in the naval arsenal of Brazil, and great credit is 

 due to the engineering officers of the Brazilian Navy, 

 not only for executing the work, but also for the 

 expedition with which it was carried out. 



Messrs. A. Gallenkamp and Co., Ltd., of Sun 

 Street, Finsbury Square, E.C.2, have sent us their cir- 

 culars describing viscometers and centrifugal machines-. 

 In the former list are placed Redwood's and Engler's 

 instruments, with details for use. No technical-school 

 laboratory or any works wherein lubricating oils are 

 largely used should be regarded as completely equipped 

 without one of these standard viscometers, for, although 

 it is possible to determine the viscosity of an oil in the 

 usual physico-chemical way, yet the conversion of 

 "absolute viscosity" to "seconds Redwood" is by no 

 means possible with accuracy in every case, and one 

 must remember that the grading of an oil is largely 

 determined by its Redwood number, and not by its 

 true viscosity. In the same list is described a convenient 

 stop-watch for timing the flow of oil. Pensky-Mar- 

 tin's, Gray's, and the Abel flash-point apparatus are also 

 included in this list. For some time past there has 

 been a demand for convenient and compact laboratory 

 centrifuges. In the circular to hand (No. 193) are 

 described hand patterns from so low a price as two 

 guineas to small power-driven instruments, built to run 

 at 5000 revolutions per minute. A modification, de- 

 signed for the rapid drying of crystals, and based on 

 the design of the works "whizzer," will doubtless be 

 found of value in many laboratories. 



