6o 



NA rURE 



[May 1 6. 1901 



section, and naturally forming part of it, will be an exViibition 

 of war kites, the uses of which will be shown. In an "Arctic " 

 section there will be, not only a large collection of Arctic 

 telics and pictures, but. also a tableau illustrating Nansen's polar 

 expedition. In the inventions section a series of the latest and 

 most valuable applications of mechanical science to the needs 

 of the Army and Navy will be on view. 



A Christiania correspondent of the Times reports that the 

 second international Hydrographic Conference held its final 

 meeting on Saturday. The object of the Conference was to 

 complete the international programme of research and the plan 

 of organisation drafted in Stockholm in 1899. The original 

 programme has been revised to meet the wishes of the partici- 

 pating Governments, and it is believed that the new proposals 

 will command such general approval as to permit of the com- 

 mencement of international investigations at an early date. The 

 Governments of all the countries bordering on the North Sea 

 and the Baltic were represented at the Conference, except 

 France, the geographical position of which gives her less 

 practical interest in the area of research. The Norwegians and 

 Russians have already provided themselves with special steamers 

 adapted to the proposed investigations, and a German steamer 

 is now being built. The arrangements of most of the smaller 

 States are well advanced. It is believed that it now rests with 

 the British Government to decide whether the international 

 programme shall be carried out or not. 



The Revue Sciintifiqtte contains an account of the first meet- 

 ing of the " Association Internationale de la Marine," held from 

 April 12 to 15 in the building of the oceanographical museum 

 at Monaco. Amongst the more important communications 

 received was one by H.S.H. the Prince of Monaco on the 

 meteorological service of the Azores, which has recently been 

 actively taken up by the Portuguese Government and is now to 

 be carried on on a very adequate scale at an annual cost of 

 45,000 francs. M. Charles Benard, president of the Societe 

 d'Oceanographie du Golfe de Gascogne, contributed a paper on 

 improvements in the equipment of vessels in case of shipwreck, 

 his proposals embodying, in particular, the suggestions of the 

 Prince of Monaco with regard to proper fishing appliances in 

 ships' boats. M. Thoulet's lithological map of the coasts of the 

 Seine Inferieure was presented, and a resolution urging the need 

 for preparing such maps of all frequented coasts, in the interest 

 both of navigators and fishermen, was adopted. The Congress 

 also declared itself in favour of the establishment of a permanent 

 Bureau Maritime Internationale, which should concern itself 

 with all maritime affairs of international interest, lighting and 

 buoyage, regulation of fisheries, assistance of sailors and the 

 tike. The Prince of Monaco, at the earnest invitation of the 

 Congress, agreed to take the initiative in attempting to bring 

 about the formation of the proposed organisation. 



This year's Deutscher Geographentag will open at Breslau on 

 Monday, May 27. On the morning of May 28 Prof. Neumayer 

 will present the report of a committee upon Antarctic explora- 

 tion, and will speak upon magnetic investigations in polar 

 regions. Dr. E. Philippi will deal with the geological problems 

 of the German Antarctic expedition, and Prof. A. Supan with 

 the Antarctic climate. At the second sitting the subject to be 

 ■discussed is the organisation of geographical instruction, the 

 speakers being Prof. H. Wagner, Dr. Auler and Herr H. 

 Fischer. On Wednesday morning. May 29, the subjects to be 

 brought before the meeting relate to the scientific study of lands 

 and native races of German colonies. The speakers will include 

 Prof. F. v. Richthofen, Prof. G. Volkens, Dr. E. Kohlschiitter, 

 Prof. K. Dove and Prof. Schenck. The methods of geographical 

 instruction will be discussed in the afternoon of the same day by 

 NO. 1646, VOL. 64] 



Dr. A. Becker, Prof. A. Fischer, Prof. A. Kirchhoff, Prof. 

 Langenbeck and Prof. A. Bludau ; demonstrations will also be 

 given by Prof. K. Dove and Dr. M. Ebeling. In the evening 

 an illustrated lecture will be given on glacier markings in 

 Montenegro, by Prof. K. Hassert, and one on the volcanoes of 

 central France by Dr. M. Friederichsen. At the fifth sitting, 

 on May 30, the papers will deal with various aspects of glaciers 

 and glaciation, and the speakers will include Profs. Finster- 

 walder, H. Meyer, S. Glmther, A. Penck, W. Goetz and 

 Dr. W. Halbfass. On the afternoon of the same day, reports 

 and papers will be received from Prof. A. Kirchhoff and C. M. 

 Kan, and Dr. K. Sapper ; and the general business of the asso- 

 ciation will be transacted. Excursions have been arranged for 

 a few days at the end of the meeting, and exhibits of geo- 

 graphical interest will be on view in two museums in Breslau. 

 The general secretary, with whom intending visitors should 

 communicate, is Dr. R. Leonhard, Schillerstr. 28, Breslau. 



In the Journal of the Quekett Microscopical Club Mr. J. 

 Rheinberg describes a simple contrivance for viewing, under the 

 microscope, the diffraction patterns of diatoms and other objects 

 of similar structure. The method adopted by Dr. Johnstone 

 Stoney is to look at the objective through a small hole fixed 

 near the usual place of the eyepiece. Mr. Rheinberg finds that 

 the diffraction patterns can be better seen above the eyepiece by 

 fixing in a short tube the objective of one of the Ts. 6d. toy 

 microscopes, which is a lens of about :J-inch focus, stopped down 

 to an aperture of about I mm. This arrangement, placed over 

 the ordinary eyepiece, shows,the diffraction patterns magnified, 

 and, further, it gives plenty of light, and the patterns cannot 

 shift. 



A \ ERV convenient addition to the laboratory or workshop 

 equipment is the rosin-cored solder recently introduced by 

 the Patent Solder Co., Ltd. This commodity is guaranteed 

 to consist of pure metals mixed in the most efficient ratio, and, 

 as its name implies, has incorporated with it the requisite 

 amount of rosin so that no additional flux is necessary. This 

 is attained by making the solder in the form of a tube with 

 narrow bore, the central cavity being occupied by the flux. 

 The two ingredients being together will facilitate work in diffi- 

 cult positions, and the cleanliness in working will be found a 

 special recommendation for electrical work. The solder is made 

 in four sizes, each of three qualities. The sizes vary from i/l6th 

 to :i-inch diameter. 



The Physical Review for March contains an article by Prof. 

 Carhart on the various determinations of the E. M.F. of the Clark 

 cell. The value originally obtained by Clark reduced to present 

 units at 15" C. is i'4378 volts, but subsequent research has 

 shown that this is somewhat too high. Prof. Carhart summarises 

 the results of eight other determinations of this constant, in five 

 of which the value was obtained by the use of the silver volta- 

 meter, the remaining three values being obtained by absolute 

 methods. The mean value calculated from the whole eight de- 

 terminations is r4335 volts at 15° C, and the mean of the 

 three absolute determinations is i'4333 volts. Prof. Carhart 

 concludes that the true value is nearer I433 ^o''^ than the 

 generally accepted value of i -434 volts. This conclusion is 

 borne out by the results of two determinations of the mechanical 

 equivalent of heat by electrical methods, in both of which the 

 values obtained are higher than those given by direct mechanical 

 methods ; if the E.M.F. of the Clark cell is taken as i 433 volts 

 instead of i '434, the discrepancies almost disappear. 



The same journal contains an interesting article by Mr. Carl 

 Kinsley on the measurement of the sensitiveness of coherers for 

 wireless telegraphy. Mr. Kinsley urges the desirability of some 



