November 14, 1912] 



NATURE 



309 



to ihe nature of these photographs, which 

 does not appear to have been the case in a letter 

 from Prof. \V. H. Bragg, which appeared in 

 Nature of October 24 (p. 219). It would be very 

 interesting if Prof. Bragg would give a revised 

 account of his views after considering these 

 crystallographic data, with which perhaps only a 

 specialist could be expected to be familiar. For it is 

 quite possible that his conclusions may still 

 prove valid when this has been done. Bui until 

 then judgment must be suspended. 



In further confirmatory experiments the crystal 

 was adjusted so that the primary Rontgen rays 

 fell perpendicularly on an octohedral face (m), 

 and subsequently on a rhombic dodecahedral face 

 (iio). In the former case the trigonal nature of 

 the symmetry axis along which the rays passed 

 was clearly revealed by three pairs of spots 

 arranged symmetrically to positions 120° apart, 

 while in the latter case the spots indicated the 

 diagonal nature of the axis by being arranged in 

 two pairs only, 180° apart. When the crystal 

 was rotated a few degrees out of exact adjustment, 

 spots of like character still appeared, but no longer 

 symmetrical to the central large spot, affording 

 another confirmation that it is the space-lattice 

 which is responsible for the photographs. 



In his Becquerel Memorial Lecture to the 

 Chemical Society on October 17, the text of which 

 is just published, 5 Sir Oliver Lodge referred in 

 the following words to a brief announcement of 

 the important work of Laue and his co-workers 

 which was made by the writer on his return from 

 Munich in September. 



This, if it be a fact, will have to be recognised as a 

 striking- and admirable case of scientific prediction, 

 the various crystalline structures and accuracy of 

 characteristic facets having been indicated by theory 

 long before there was any hope of actually seeing 

 them ; so 'that once more — always assuming that the 

 heralded discovery is substantiated — the theoretical 

 abstraction will have become concrete and visible. 



It will now be clear, from the detailed memoirs 

 just published, that the writer's announcement is 

 full>- substantiated. Crystallography thus affords 

 to its sister science Chemistry the first 'visible 

 prcjof of the accuracy of Dalton's atomic theory, 

 and now enters into a new sphere of still greater 

 usefulness. The important work of von Fedorow 

 on crystallochemical analysis, described in the 

 writer's last communication to Nature {\oc. cit.), 

 is based essentially on the assumption of the space- 

 lattice structure of crystals which is now rendered 

 visible to our eyes, for the centres or analogous 

 points of his parallelohedra form either one of the 

 fourteen space-lattices or one of nine simple 

 Sohncke point-systems composed of interpenetrat- 

 ing space-lattices ; that work is thereby enhanced 

 in value and placed on an absolutely trustworthy 

 basis. Crystallography has thus become an 

 exact science leading us to a practical knowledge 

 of the hitherto mysterious world where Dalton's 

 atoms and molecules reign supreme. 



A. E. H. TuTTON. 



3 Journ. Chem. S-^r. Tr.-r'.. '^rtober, 1912, CI, 20i8. 



NO. 2246, VOL. go] 



GEOPHYSICAL MEMOIRS.'^ 



BY the authority of the Meteorological Com- 

 mittee, and under the style and title of 

 Geophysical Memoirs, the publication of a series 

 of investigations has been commenced with the 

 issue of the four " blue-books " before us. It is 

 evident that a high standard of value is contem- 

 plated ; if possible, higher than that of previous 

 " Reports of Investigations in Dynamical and 

 Statistical Meteorology," which appear in the 

 same section of Meteorological Office publications. 

 We shall look forward with interest to the suc- 

 ceeding memoirs, which represent a genuine 

 attempt to dispel the reproach often cast upon 

 meteorologists as mere collectors of undigested 

 statistics with no real claim to the title of men 

 of science. 



The subjects of the memoirs already received 

 are quite independent. In No. i, the Marine 

 Superintendent of the Meteorological Office 

 (Campbell Hepworth, Commander R.N.R.) dis- 

 cusses the effect of the Labrador current upon the 

 surface temperature of the North Atlantic, and of 

 the latter upon air temperature and pressure over 

 the British Isles. It is interesting, in view of the 

 vagaries of the latter within even the last eighteen 

 months, to find it definitely stated that the much- 

 discussed prevalence of ice in the Atlantic is not 

 a cause of cold weather here, but only a sym- 

 ptomatic effect of the cold Lalarador current, the 

 meeting of which with the Gulf Stream is held 

 responsible for the notorious fogs off the banks of 

 Newfoundland. The discussion of the data for 

 1903 to 1907 and for most of 191 1 is illustrated by 

 an interesting series of plates giving mean sea- 

 surface isotherms of the North Atlantic for 

 January, April, July, and October, thermo-isopleths 

 for surface temperature between Florida Straits and 

 Valencia (Ireland), mean annual surface tempera- 

 ture for every 2° square in the North Atlantic, 

 and separate diagrams for each of the years under 

 discussion, giving monthly prevalence of ice in 

 the Atlantic measured by 1° squares in which it 

 was observed, the sea temperature, and the air 

 temperature and pressure for three British coast 

 stations, Sumburgh Head, Shields, and Valencia. 

 The author's great experience, both at sea and in 

 the office dealing with the mass of observations 

 communicated from ships, renders his views 

 especially worthy of consideration. 



In No. 2, Mr. W. H. Dines, the foremost 

 British investigator of the upper air, continues 

 some previous work with discussions of the vertical 



1 f i) " The Effect of ttie Labrador Current upon tlie Surface Temperature 

 of the North Atlantic, and of the latter upon the Air Temperature and 

 Pressure over the British Isles." By Commander M. W. C. Hepworth, C.B., 

 Pp. 10+9 plates. Price g</. 



(2) ''I'he Free Atmosphere in the Region of the British Isles. Further 

 Contributions to the Investigation of the Upper Air, comprising the Vertical 

 Ten.perature Distribution in the .Atmosphere over England, with some 

 remarks on the General and Local Circulation ; Abstract of a paper printed 

 in Volume ccxi of the Philosophical Transactions, Series A, and Total and 

 Partial Correlation Coefficients between Sundry Variables of the Upper 

 Air." By W. H. Dines. F.R.S. Pp. r 1-50+ plates to-12. Price ij. 



(3) " Graphical Construction for the Epicentre of an Earthquake." By 

 G. W. Walker. Pp. 51-54 + plate 13. Price 3</. 



(4) "On the Radiation Records obtained in 1911 at South Kensington, 

 together with a comparison between them and the Corresponding Absolute 

 Observations of Radiation made at Kew Observatory. ' By R. Corless. 

 Pp. 55-61 + plate t4. Price 3<f. (London : H.M. Stationery Office and the 

 M leurological Office, 1912). 



