December 26, 1912] 



NATURE 



471 



Meteorological Office, part i., 1912). The investig-a- 

 tioti is based on observations from 1892-1906 at 120 

 stations, at which no interruption had taken place 

 during the period. The tables include monthly, 

 seasonal, and j'early mean values of the daily maxima 

 and minima, and of their difference (or mean daily 

 range), each being separately treated, except in the 

 annual summary. This special treatment of the 

 various data, especially of the daily range, is of con- 

 siderable climatic interest. The author also gives, 

 for all stations, the value for each month and season 

 of the varying coefficient involved in Kamtz's for- 

 mula for obtaining true daily means of temperature. 

 Among many useful results it is noted that, generally 

 spi-aking, the effect of latitude is not very distinctly 

 shown in the annual values of the maxima and 

 minima, owine to the many local influences at work. 

 The annual range is greatest in the interior, especially 

 ill L'pper Italy, where, proceeding inland from the 

 .Adriatic coast, constantly increasing values occur. 



The International Geodetic Conference, which met 

 at Hamburg in September last, among other impor- 

 tant questions discussed the subject of the precision 

 of a level network, and laid down a new standard of 

 accuracy for " nivellements de haute precision." Such 

 a standard will doubtless prove of great value to the 

 directors of large surveys plannning new levelling 

 work, and it will be interesting to see a detailed dis- 

 cussion of the errors of an actual reseau compared 

 with the limiting errors calculated from the formulae 

 approved by the conference. Short ot this, it is not 

 possible to institute a strict comparison between the 

 two. but it would appear that good modern work, 

 such, for instance, as the Indian Survey Department's 

 precision levelling, falls well within the prescribed 

 limit. The thanks of all geodesists are due to Lieut.- 

 Col. Lallemand for the trouble he has taken in this 

 matter, and for his long-continued and most valuable 

 contributions to this branch of geodesy. Pending the 

 publication of the conference volume, a summary of 

 the formulae in question will be found in the Comptes 

 rendiis of the Paris Academy of Sciences for October 

 14, 1912. 



The indefatigable and distinguished seismologist, 

 Dr. F. Omori, in vol. v., No. 7, of the Japan Astro- 

 nomical Herald, has branched off on a new line and 

 given us an interesting and instructive article on the 

 variation of latitude and changes in the mean sea-level 

 of Japan. First we are introduced to a table which 

 gives in millimetres mean sea-level in successive years 

 at nine stations round the coast of Japan. A glance 

 at this shows that although sea-level during twelve 

 months may have increased at one station, at other 

 stations during the same period it may have decreased. 

 The greatest fluctuations appear to have taken place 

 at Misaki, which lies just outside the Bay of Yedo. 

 In 1897 the sea-level at this place remained constant, 

 but bv 1909 it had risen 166 millimetres. An annual 

 average value of the records of nine stations, when 

 they are plotted on squared paper, show that sea-level 

 was low in 1897 and 1902, but it was high in 1899 

 and 1905. Beneath this diagram Dr. Omori has given 

 NO. 2252, VOL. 90] 



a curve showing changes in latitude as observed at 

 Tokyo and Mizusawa. The resemblance between 

 these two diagrams is very striking, and from them 

 it appears that a variation of o"'i in latitude is accom- 

 panied by a change of 42 millimetres in sea-level. 



A p.APER on searchlights for the mercantile marine, 

 read before the Manchester Literary and Philosophical 

 Societv by Dr. Henry Wilde, F.R.S., on May 7, was 

 reported and commented upon in the issue of Nature 

 for May 30 (vol. l.xxxix., p. 325). On November 12 

 Dr. Wilde returned to the question in a paper, entitled 

 "On Searchlights and the Titanic Disaster," which he 

 read to the same society. In this paper he passes in 

 review the evidence given in connection with the use 

 of searchlights in the report on the loss of the Titanic, 

 and also the statements in the report of the Merchant 

 Shipping Advisory Committee of the Board of Trade. 

 After considering these reports. Dr. Wilde concludes 

 his paper thus : — " In view of the facts brought out 

 by the several committees engaged in investigating 

 the causes leading to the loss of the Titanic, it only 

 remains for me to repeat and to emphasise the state- 

 ment made in my paper read before the society in 

 May last, that the ultimate responsibility of a calamity 

 which the world deplores rests upon the British naval 

 authorities through their fatuous policy of excluding 

 searchlights from the Mercantile Marine." 



In the Journal de Physique for November, M. J. 

 Bosler, in a paper on the relations between magnetic 

 storms, earth currents, and solar eruptions, puts for- 

 ward a theory of the production of magnetic storms 

 which he believes to be new. He was, it appears, led 

 to it by finding that the horizontal component of the 

 disturbing force in a magnetic storm is on the average 

 at right angles to the direction of the earth current 

 observed at the same instant at the same station, and 

 that these currents flow at each station in a direction 

 which is nearly constant. At Pare Saint Maur, near 

 Paris, for example, the direction is in general from 

 north-east to south-west. M. Bosler considers these 

 currents the cause of magnetic storms, and explains 

 them as due to the expression for the magnetic induc- 

 tion through the earth having in it a variable term 

 owing to electrified matter projected from the sun. 

 This variable term would result in an electric current 

 about the earth which in turn would produce a mag- 

 netic disturbance. Unfortunately, the author does not 

 indicate how the term expressing the variable induc- 

 tion arises, nor does he trace the consequences of his 

 theory any further. It seems^ for example, to demand 

 that magnetic storms should be most intense at any 

 instant in the great circle perpendicular to the variable 

 magnetic induction, a conclusion which might have 

 been tested by comparison with observations. 



Prof. C. Ravenn.a and Mr. G. Bosinelli describe 

 in the Atti R. Accad. Lincei (vol. xxi., ii., 355) further 

 experiments to ascertain whether the traces of 

 hydrogen cj'anide found in young plants exist therein 

 in the free state, or solely in the form of cyanogenetic 

 glucoside from which they are liberated by the action 

 of an enzyme under the conditions of making the test. 



