288 



NATURE 



[June i, 1916 



jects into a spiral of Archimedes, and Grandi applied 

 the same method to the curve of wliich the projection 

 is an equiangular spiral. 



The October-November part and the December 

 (1914) part of the Journal de Physique, which were 

 published in the earlier part of May, complete 

 vol. iv. of the journal. Amongst the longer papers 

 contained in the two parts may be mentioned one by 

 Prof. Marcel Brillouin on kinetic energy and absolute 

 temperature in isotropic solids, the concluding portion 

 of Prof. Seligman-Lui's paper on the mechanical inter- 

 pretation of the law of gravitation. Prof. Gour6 de 

 Villemont6e's paper on the propagation of electricity 

 through paraffin oil, and Prof. E. Bouty's paper on 

 some exainples of the application of the method of 

 closed cycles. In addition, there are shorter papers 

 on the localisation of foreign bodies in the organism 

 by radiographs, and on the recent determination of 

 the latent heat of fusion of ice at the Bureau of 

 Standards at Washington. The abstracts of papers 

 published in other journals include a number in the 

 Philosophical Magazine, Journal de Chimie-physique , 

 Annalen der Physik, Physikalische Zeitschrift, and the 

 Zeitschrift fiir Physikalische Chemie. The author 

 index of the volume covers twenty, the analytical 

 table of contents sixteen, and the volume 850 pages. 



Mr. a. L. Parson has published a novel theory of 

 the constitution of atoms based on a new conception 

 of the structure of the electron (" A Magneton Theory 

 of the Structure of the Atom," Smithsonian Miscel- 

 laneous Collections," vol. Ixv., No. 11). Instead of the 

 usual assumption that the electron possesses spherical 

 symmetr}-, the author considers it to be a ring of 

 negative electrification revolving with high speed. 

 The diameter of the ring is supposed to be of the same 

 order of magnitude as atomic diameters, and the tan- 

 gential velocity of revolution to be about the velocity 

 of light. The author points out that these assump- 

 tions are not inconsistent with the experiments on 

 which our knowledge of the electron is based, and 

 shows that they offer a mode of escape from certain 

 well-known diflficulties in all theories of atomic struc- 

 ture based on the usual assumptions of simple elec- 

 trons. In the paper the application of the new con- 

 ception to the explanation of the chemical and mag- 

 netic properties of the elements is discussed at con- 

 siderable length, but it may be noted that all the 

 considerations are only of a qualitative character, and 

 do not provide any definite test of the adequacy of 

 the theory. It should be added that no use is made 

 of the recent valuable and extensive evidence as to the 

 structure of atoms derived from the studv of the 

 phenomena of radio-activity and X-rays, and. indeed, 

 it seems difficult to account for them on the new 

 theor}'. 



Mr. F. C. Thompson, in a paper recently read before 

 the Faraday Society, directs attention to the fact that, 

 almost without exception, alloys which are of indus- 

 trial utility consist of one or more solid solutions. 

 The brasses, nearly all the bronzes, the nickel brasses, 

 most coinage alloys, aluminium alloys for aeroplane 

 and motor-car construction, fall within this category. 

 The hardening of steel is due to the formation, and 

 more or less complete preservation on quenching, of 

 a solid solution. The special properties of the nickel 

 and nickel chromium, steels are due to the improve- 

 ment conferred by the alloving element or elements 

 which dissolve in the iron. The dominating character- 

 istic of these alloys as compared with the pure metals 

 from which they are made is " toughness," a combina- 

 tion of strength and ductility. As a result of his 

 study of the matter, Mr. Thompson concludes that the 

 remarkable hardness and high electrical resistivity of 



NO. 2431, VOL. 97] 



solid solutions of metals point strongly to the fact 

 that they are caused by crystalline distortion similar to 

 that which arises from cold work. This is explained 

 on the theory that the process of crystallisation of such 

 solutions causes an equalisation of the atomic volumes 

 of the constituents. Elastic stresses are thus set up 

 which, in their turn, increasing the resistance to further 

 stresses, raise the hardness of the mass. Such a theory 

 would lead to a parabolic curve expressing the relation- 

 ship of the hardness to the concentration throughout 

 the series, with a maximum at the composition of 50 

 atomic per cent, of each metal. The silver-gold series 

 of alloys fits into this generalisation. 



Technologic Paper No 68 of the U.S. Bureau of 

 Standards -deals with standardisation of automobile 

 tyre fabric testing. The chief causes of variation in 

 test results are due to different testing machines, 

 dimensions of test specimens, moisture content of 

 specimen at time of test, method of sampling, and lack 

 of uniformity in the material. There is but little 

 difference ip the results for strips of i in. and 2 in. 

 width, and the former width has advantages which 

 indicate that preference should be given to it. The 

 fabrics were supposed to contain twenty-three threads 

 per inch, and the actual width of the specimens was 

 fixed by counting twenty-three threads. The average 

 strength of thirty tests on i-in. specimens was 247 lb. 

 Samples of cotton material increase in strength con- 

 siderably when they have absorbed moisture from the 

 atmosphere. It is best to dry the sample in such a 

 way as to eliminate moisture effects entirely. There 

 are only small differences in strength for specimens 

 selected from different parts of the width of the fabric; 

 samples should be cut from different parts, and the 

 average result taken. Tests made in different 

 machines show differences amounting to as much as 

 159 per cent. It is recommended that testing 

 machines be calibrated at frequent and regular in- 

 tervals. 



OUR ASTRONOMICAL COLUMN. 



Large Daylight Fireball on May ap. — Mr. Den- 

 ning writes : — " On May 20, at 8.8 p.m. (18 minutes 

 after sunset, Greenwich), a splendid meteor was seen 

 by a great many persons in the southern counties of 

 England. The sky was clear everywhere, and the 

 large green disc of the meteor created a vivid effect 

 as it passed with a rather slow, apparent motion from 

 N. to S. across the western heavens. Reports from 

 fifty-six casual observers of the phenomenon have 

 been received, and it appears from a preliminary dis- 

 cussion of the data that the object was directed from 

 a radiant in Perseus situated in the N.N.W. sky at the 

 time of the event. The height of the meteor was 

 from about 75 to 27 miles along a course, slightly 

 declining in height, of more than 2co miles. The posi- 

 tion was from over the S.E. coast of Ireland to_ the 

 English Channel, far south of Devonshire. 



"The estimates of the observed duration of flight of 

 the meteor are rather conflicting, but, taking a mean 

 of what appear to be the best values, the real velocity 

 was about 32 miles per second. 



"This fine meteor adds another instance to the 

 rather extensive list of similar objects which have 

 made their apparitions in twilight. The hour follow- 

 ing sunset is highlv favourable in some respects to 

 the production of these objects, though the prevail- 

 ing daylight must naturally cause many of them to 

 elude notice." 



Comet iqT6& (Wolf), 19 16 ZK (Planet). — From 

 Astronomische Nachrichten, No. 4845, we learn that ob- 

 servations of the anomalous object igi6 ZK, discovered 



