538 



NATURE 



\OcL 12, 1876 



M. Krantz intends to imitate on a smaller scale the great 

 Hell Gate explosion by opening in a similar manner the ground 

 of the Champ de Mars, and thus expediting the excavations for 

 the erection of the basement of the Exhibition building. 



The French papers give some figures with reference to the 

 iron framework of the building now constructing. The weight 

 required for the machine gallery will be 17,000 tons, and 

 for other galleries 10,000 tons. To these 27,000 tons of iron or 

 cast-iron may be added 700 tons of sheet ^iron for covering the 

 building. The superficial extent of carpenter work for battening 

 the roof will be 90,000 square yards covered with zinc. The 

 quantity of the wood necessary is about 2,000 cubic yards. The 

 number of rivets used for bolting the metallic frame will be 

 11,000,000, and the number of holes to be perforated a little 

 more than double, viz., 23,000,000. 



Among the lectures to be given at the Nottingham Literary 

 and Philosophical Society during the coming winter, are one by 

 Dr. Ball, F.R.S., November 9, "A Night at Lord Rosse's 

 Telescope," and another on December 7, by Dr. M, Foster, 

 F.R.S., "On Nerves." 



The following are some of the scientific works to be published 

 during the coming season : — The second series of Mr. George 

 Henry Lewes' "Problems of Life and Mind," entitled "The 

 Physical Basis of Mind," is in the press, and will be published 

 by Messrs. Triibner. The same publishers are preparing for 

 publication in December, "Theoretical Mechanics," a Manual of 

 the Mechanics of Engineering and of the Construction of Ma- 

 chines, with an Introduction to the Calculus ; designed as a 

 text-book for technical schools and colleges, and for the use 

 of engineers, architects, &c., by Julius Weisbach, Ph.D., 

 Professor at the Royal Mining Academy at Freiberg. It 

 is translated from the fourth augmented and improved Ger- 

 man edition by Eckley B. Coxe, A.M., Mining Engineer. 

 With woodcuts. — Me=srs. Bentley and Son have in the press a 

 narrative of travel in Norway and Lapland, by Mr. S. H. 

 Eden, to be called " Within the Arctic Circle." — We are glad 

 to notice that Messrs. Chatto and Windus are preparing a new 

 edition of ' ' Wilson's American Ornithology ; or, Natural History 

 of the Birds of the United States ; " with the continuation by 

 Prince Charles Lucien Bonaparte ; completed by the insertion 

 of above one hundred birds omitted in the original work, and 

 illustrated by notes and a life of the author by Sir William Jar- 

 dine. — Among Messrs. H. S. King and Co.'s announcements we 

 observe: — "The Large and Small Game of Bengal and the 

 North- Western Provinces of India," by Capt. J. H. Baldwin, 

 F.Z.S., Bengal Staff Corps, with numerous Illustrations. 

 " Studies in Spectrum Analysis," by J. Norman Lockyer, 

 F.R.S., "The Races of Man and their Geographical Distri- 

 bution," from the German of Oscar Peschel. This last-named 

 book is ready. — Prof. Tyndall's " Lessons in Electricity at the 

 Royal Institution," will be published by Messrs. Longmans at 

 the end of this month. 



The additions to the Zoological Society's Gardens during the 

 past week include two Silky Marmosets {Hapalt chrysoleucus) 

 from S. E. Brazil, presented by Master T. A. Brassey ; a Green 

 Monkey {Cercopithecus callitrichus) from W. Africa, presented 

 by Mr. Chas. L. N. Ingram ; an Entellus Monkey {Semnopithecus 

 entellus) from India, presented by Mr. Edwin Penn ; two Coatis 

 {N^asua nasica) from S. America, presented by Mr. J. A, Watson; 

 a Vulpine Phalanger {Phalangista vulpina) from Australia, pre- 

 sented by Mr. Graham M. Sutton ; four European Terrapins 

 {Clemmys europea), European, presented by Mr. Edward W. 

 Bonham ; two Tora Antelopes {Alcelapkus tora) from S. Africa, 

 purchased ; two Scemmerring's Antelopes {Gazella scemmerringi) 

 from S. Africa, deposited ; a Crested Y\^^ox\.{0cyphap5 lophotes), 

 bred in the Gardens. 



SCIENTIFIC SERIALS 



Foggendorff'' s Annalen der fhysik und Chemie, No. 8, 1876. 

 — This interesting number commences with a paper by M. 

 Zollner, investigating a class of electrical phenomena that do not 

 appear to have been previously studied. When two different 

 bodies, an insulator and a half-conducting rubbing instrument are 

 rubbed together, electrical currents occur in the rubber, as 

 follows : — If the rubbed insulator be positively electric, the 

 currents at the surface of contact or in the interior of the rubber 

 are parallel, but opposite to the relative motion of the insulator ; 

 if the latter be negative, the currents of the rubber are parallel, 

 and in the same direction as the insulator's motion. These 

 currents were measured, and shown to be often very consider- 

 able, and they could be^intensified by multiplying the rubbers and 

 connecting their corresponding parts with wires. They lessen the 

 useful effect of an electric machine, and an advantage is had by 

 uniting the electricity at the positive end of the rubber with 

 the positive electricity of the conductor. M. Zollner is led to 

 study a variety of related experiments, e.g. the currents generated 

 in flow of water through a thin tube. He arrives at this general 

 result : Diaphragm-currents and their modifications are due to 

 the occurrence of new electromotive forces, such that the electric 

 current they generate in the moved liquid, so long as it is in 

 contact with the canals of the diaphragm or the capillary tube, 

 are always opposite to an electric current which would force the 

 liquid in the same direction through the diaphragm as the 

 mechanical pressure. — From experiments made with caoutchouc, 

 carbonic acid, and hydrogen, on the diffusion of gases through 

 absorbing substances, M. Wroblewski concludes that the velocity 

 with which a given quantity of gas diffuses through a caoutchouc 

 membrane is proportional to the pressure of the diffusing gas on 

 the membrane. — A paper on the radiometer is contributed by M. 

 Finkener ; the object of the experiments was to show the influence 

 of change of gas, pressure, and radiant heat on the instrument. 

 He finds (i) that with rarefaction not carried too far, and with 

 equal heating, a given motion takes place at a greater pressure 

 in a specifically lighter gas than in a heavier one ; (2) the turning 

 force excited by the flame increases at first (other circumstances 

 the same) with the rarefaction of the gas, but with further rare- 

 faction decreases ; (3) this maximum occurs at a greater pressure 

 with hydrogen than with airjand carbonic acid. M. Finkener offers 

 an explanation of the motion, deduced from these phenomena. 

 — The law of colour-mixture may be studied by superposing dif- 

 ferent parts of two spectra, or looking at a glass plate from which 

 a surface of one colour is reflected while another colour is seen 

 through it, or by means of the persistence of impressions from a 

 disc with variously coloured sectors or rings set in rapid rotation. 

 M. Bezold here gives another and still more convenient 

 method. You look through a prism of Iceland spar set in a 

 tube blackened interiorly, which is closed below by a disc with 

 four squares cut out of it. The prism gives double images of 

 the squares, and in a certain position two of the eight are 

 brought to coincide with other two in the middle. Surfaces of 

 different colours being brought under the two squares occupying 

 (say) the upper row, their composite colour is obtained in the 

 middle image, and then may be found what colour must be put 

 under the lower two squa'-es to obtain a colour in the middle 

 corresponding to the one above. — Dr. Berthold collects some 

 interesting early indications of a knowledge of the phenomenon 

 of fluorescence as shown by an infusion of nephritic wood. It 

 is remarkable that though Priestloy, Fischer, and Wilde referred 

 at some length to the observations made by Kircher, Boyle, 

 Newton, Wolff, and Wunsch, on fluorescence, the facts should 

 have been almost entirely forgotten till our time. — Studying the 

 influence of temperature on the galvanic conductivity of tellu- 

 rium, M. Exner finds that the seemingly quite irregular resistances 

 of the metal after repeated heatings stand in direct relation to 

 the time of heating and of cooling, a circumstance which must 

 be connected with the crystalline structure of tellurium at low 

 temperatures. — Among the remaining papers we note accounts 

 of an apparatus for combination of vibrations at right angles to 

 each other (Stohrer), a new hydrometer (Sedlaczek), and an im- 

 proved poison syphon (Antolik). 



Sihungsberichte der naturwissenschaftlichen Gesellschaft Isis 

 in Dresden, January to June, 1876. — From this publication we 

 note the following papers of importance : — Alineralogical and 

 Geological Section. — Geognostical researches on the Leitmeritz 

 mountains, by Herr Engelhardt. — On the Velino fall near Terni, 

 by C. Bley.— On the silver and gold mines in the neighbourhood 



