June 28, 1894J 



NA TURE 



203 



tion to aerial navigation of data on the resistance of air, and 

 the development of the motors required to render such means of 

 transport an accomplished fact. From this summary it will be 

 seen that the Congress has been organised not only with the idea 

 of bringing together those who are working at the problem of 

 aerial navigation, but also meteorologists, naval architects, and 

 all whose experiences may help to elucidate the matter. The 

 President of the Congress is Lieut. -General Wauwermans, and 

 the General ijecretary, Chevalier Le Clement de Saint 

 Marcq, Rue du petit Chien, i6, Antwerp. M. Lancaster, of 

 the Brussels Observatory, is the President of Section L, and 

 Captain M. van den Borren, the President of Section IL 



Everyone will agree that the Marine Biological Association 

 of the United Kingdom has, since the opening of the Labora- 

 tory, six years .igo, carried out the intentions of its original 

 supporters, which were * ' to promote researches leading to the im- 

 provement of zoological and botanical science, and to an increase 

 of our knowledge as regards the food, life, conditions, and 

 habits of British food-fishes and molluscs." Scientific research, 

 however, is not often generously endowed, hence the .\ssocia- 

 tion, like many similar institutions for investigation, has its 

 activity greatly restricted by the need for further financial sup- 

 port. With the idea of showing the truly national importance 

 of the work carried on in the Laboratory at Plymouth, the 

 Association has issued a pamphlet, in which its aims are briefly 

 stated, and a few of the many practical and purely scientific 

 investigations carried out under its auspices are described. It 

 is hoped that this statement will quicken interest in marine 

 biology, and induce benefactors to science to give their support 

 to its representative Association, not only because their assistance 

 will help to extend scientific knowledge, but also because they will 

 be assisting in the development of our sea-fisheries. The follow- 

 ing extract from the pamphlet referred to shows how small are 

 the funds of the Association in comparison with those of other 

 establishments having similar objects: — "The income of the 

 Association is derived partly from a grant by the Treasury, 

 partly from the voluntary generosity of public companies and 

 private individuals. The Fishmongers' Company contribute 

 ;^400 a year to the -Association, whilst Her Majesty's Govern- 

 ment have given ;^500 a year in the years 1888-9, 1889-90, 

 1890-91, and p^'iooo a year in the years 1891-2, 1892-3, and 

 1893-4. The total income unfortunately falls considerably 

 short of the amount necessary to place the Laboratory on a 

 properly efficient footing. The purchase and maintenance of a 

 sea-going steam-vessel, by means of which fishery investiga- 

 tions can be extended to other parts of the coast than the imme- 

 diate neighbourhood of Plymouth, is a most pressing need. The 

 admirable Marine Biological Laboratory at Naples, founded and 

 directed by Dr. Dohrn, and devoted purely to zoology and 

 botany, has cost about ;f 20,000, including steam-launches, &c., 

 whilst it has an annual budget of £loao. The United States 

 Fish Commission receives from its Government more than 

 ;^70,ooo a year, and possesses a perfect fleet of vessels. Its work 

 almost exclusively relates to fisheries. The .Scottish Fishery 

 Board is credited in the estimates for 1893-4 with ^21,858, 

 which (with the exception of .^£^3000 for pier and harbour works) 

 is granted for fresh and salt water fishery work. The Marine 

 Biological Association, with the twofold aim of promoting pure 

 zoology and scientific fishery investigation, received in 1892-3 

 only £i\<)^ in all." We trust that the appeal of the Associa- 

 tion will result in a large extension of the list of subscribers, 

 so that biological science and the fishing industry may both be 

 benefited. 



A RECENT number of the Comptes licndus contains a note, by 

 M. Birkeland, on some recent work done in the late Prof. 

 Hertz's laboratory. It is well known that Hertzian waves 



NO. 1287, VOL. 50] 



when they travel along an iron wire magnetise it transversely, 

 although they only penetrate a very short distance below the 

 surface of the wire. This being so, it was an interesting problem 

 to investigate whether it would be possible to observe in such a 

 wire nodes and loops in the magnetisation. Experimenting in 

 this direction M. Birkeland was led to a negative result, which 

 he attributed to the electrical conductivity of the wire, and 

 hence he was led to experiment, not on cylinders of iron, but 

 on mixtures of finely divided iron and paraffin. He uses a 

 square resonator having each side 60 cm. long, the opposite 

 side to the spark micrometer being formed into a coil of twelve 

 turns, well insulated from each other. If a cylinder of soft iron is 

 introduced into this coil, the spark length is not changed ; a fact 

 which previous experimenters have shown to be due to the 

 screening effect of the induced currents in the superficial layer 

 of the mass of metal. When, however, a cylinder of the 

 mixture of iron and paraffin is introduced into the coil, the 

 spark length may be reduced from 9 m.m. to 005 m.m. or to 

 i/i8oth of its original value. The effects observed increase as 

 the electrical conductivity of the cylinders diminish, so that the 

 magnetic action of the iron becomes less masked by the con- 

 ductivity effects. This is well shown by surrounding the 

 cylinder with tin-foil, when the spark regains its original length. 

 When a hollow cylinder of the mixture of iron and paraffin is 

 introduced into the coil, the spark length is much shortened, 

 but the effect is much enhanced when the hollow cylinder is 

 filled by a solid rod. Thus the author finds that the magnetic 

 action is felt through a thickness of 5 m.m. when the mixture 

 contains 25 per cent, of iron, and through 7 m.m. when it 

 contains 10 per cent of iron. 



The Central Meteorological Office of France has just pub- 

 lished its Annah-s for the year 1&92, consisting of three large 

 quarto volumes. Vol. i. contains a number of memoirs on 

 special subjects, among which, as usual, there is one by M. 

 Fron, on thunders;orms in France during the year. These 

 summaries have been continued for thirty years, and furnish use- 

 ful data for determining the laws which underlie the formation 

 and propagation of those phenomena. M. .Moureaux discusses 

 the observations on terrestrial magnetism at the Pare Saint 

 Maur, and gives curves from the self-recording instruments of 

 the most remarkable disturbances, which were considerable 

 during that year. He also contributes a paper on the magnetic 

 conditions at 100 stations; there are altogether 42S such stations 

 in France ; those not yet dealt with will be discussed in subse- 

 quent years. The results of phenological observations and the 

 migrations of birds during the years 18S1-90 are discussed by 

 M. Angot ; this is one of the most comprehensive and complete 

 papers of the kind hitherto published. He aho contributes a 

 valuable paper on the results of M. Vallots first series of observa- 

 tions on the summit of Mont Blanc, made in 18S7, and a com- 

 parison of the simultaneous observations made at the central 

 office in Paris and on the Eiffel Tower, which confirm the 

 principal results obtained in previous years. Finally, M. 

 Durand-Greville gives a detailed investigation of the connection 

 between squalls and thunderstorms, and has determined some 

 of the phenomena which regularly accompany the formation and 

 propagation of the latter. Vols. ii. and iii. deal respectively 

 with the ordinary observations and with rainfall values at a large 

 number of stations. An important addition to this branch of the 

 work has been made by the publication of the observations 

 made in Senegal, among those referring to stations for various 

 foreign places. 



At the joint meeting of Cornish scientific societies, held at 

 Penzance on June 15, Mr. Howard Fox, the president of the 

 Royal Geological Society of Cornwall, read a paper on " Some 

 Fossils from the Coast Sections in the Parishes of Padstow 



