April lo, 1884] 



NATURE 



565 



Mr. H. H. West read a paper on the Riveting of Iron Ships, 

 sjiving tables for calculating the plate and rivet area for double- 

 riveting, treble-riveting, and quadruple-riveting. He referred 

 to the researches of Sir Edward Reed, the Institution of 

 Mechanical Engineers, and others, but did not mention the 

 modification of treble-riveting proposed some years ago, and 

 lately carried into effect by a firm in Holland. On this system, 

 in the middle row of the three rows of rivets, the rivets are 

 spaced only half the distance apart of the two outer rows, the 

 result being to increase very largely the proportion of strength. 

 Capt. Heathorn described an arrangement called by him a 

 Water-brake, for stopping the way of a ship in cases of collision 

 or otherwise ; and finally, Mr. J. E. I.iardet described an appa- 

 ratus for indicating the position of a ship's helm. 



On the whole the Institution is to be congratulated on the 

 interest and importance of the papers provided for it, and 

 still more on the vigour and ability with which they were dis- 

 ciLssed by the very eminent engineers and shipbuilders who 

 thronged the rooms of the Society of .\rts for the purpose. 



SCIENTIFIC SERIALS 



Bulletin de V Acadcmie R. de Belgijue, January 5. — On the 

 existence of a fourth species {B. borealis) of the genus Balajn- 

 optera in the North Atlantic and .'\rctic Oceans, by M. 

 Guldberg. — On the action of clilorine on combinations of sulphur, 

 .ind on organic oxysulphurets, third communication, by M. W. 

 Spring. — Researches on speniiatogenesis in the Selacians (Scyl- 

 titim catulus, Sc. canicula, Raja clavafa), the salamander and 

 mammals, by Prof. A. Swaen. — Essays on the political history 

 'if the last three centuries, by M. Van Praet. — Biographical 

 notice of the painter Michael Van Cocxyen of Mechlin, by M. 

 Castan. 



A/li dslla R. Accademia del L'nrei, January 20. — Letter from 

 King Humbert announcing an additional annual grant of 400/. 

 for the promotion of biological studies, to be distributed in prizes 

 in any way the Academy may think fit. — Some philological 

 remarks on the 104th Psalm, by Guidi Ignazio. — Notice of an 

 unpublished work of Prince Federico Cesi, entitled "De Laser- 

 piteo et Laserpitii pluvia," in the library of the Botanic Institute 

 at Padua, by Prof. A. Favaro. — Note on the antiquities disco- 

 vered at Ventimiglia, Montefiascone, Naples, Pompeii, and 

 other parts of Italy during the month of December 1883, by S. 

 Fiorelli. 



February 3 and 4. — Notice of some unpublished writings of 

 Oalileo Galilei in the National Library of Florence, by Prof. 

 Favaro. — Report on Prof Bellonci's work " On the Segmenta- 

 tion of the Egg of the Axolotl," by S. Trinchese. — Report on 

 Dr. G. Frattini's work "On Some Propositions in the Theory 

 of Substitutions," by S. Battaglini. — Report on Dr. L. 

 Macchiati's work on the chemical nature of chlorophyll, by S. 

 Cannizzaro. — Observations of the solar spots and faculse made at 

 the Observatory of the CoUegio Romano during the year 1883, 

 by Pietro Tacchini. — On the temperature corresponding to the 

 Glacial period, third note, by Pietro Blaserna. — On the extra- 

 ordinary crepuscular phenomena observed during the last few 

 months, by Lorenzo Respighi. — Contributions to the study of 

 the carbopyrolic acid a, by G. L. Ciamician and Paolo Silber. — 

 Remarks on the Veronese Chelonian { Pi otosphargis z'C-onensis) 

 discovered in 1852 in the Upper Chalk near St. Anna di 

 Alfaedo in Valpolicella, by Giovanni Capellini. — Geological 

 observations on the islands of the Tuscan Archipelago, by B. 

 I^tti. — Reports on the competition for the Royal Prizes for 

 Physics, History, and Geography for the year 1882, by Signors 

 Cantoni and Villari. — Reports on the Ministerial prizes for the 

 Philosophical, Social, and Natural Sciences for the year 1883, 

 by Signors Bonatelli and Trinchese. 



February 17. — Obituary notices of the late Pietro Canal and 

 Edoardo Laboulaye, Members of the Academy, by the President. 

 7— On the practice of burying human bones stripped of the flesh 

 in Neolithic times, by Luigi Pigorini. — Note on the antiquities 

 discovered at Felonica, Este, Imola, and in other parts of Italy 

 during the month of January 1884. — Remarks on some codices 

 in the Angelica Library connected with patristic theology, by 

 Enrico Narducci. — Note on the parabolic orbit of the comet (e) 

 discovered by Hartwig at Strasburg on August 24, 1879, by E. 

 Millose\'ich. — On a remarkable disposition of the isogonic lines 

 of terrestrial magnetism observed in the eastern districts of the 

 Valley of the Po (two illustrations), by Ciro Chistoni. 



Rivisla Scienti/ico- [mlusti iale, February 15 and 29. — Descrip- 

 tion of a new apparatus for the measurement of electro-motor 

 forces (four illustrations), by E. Reynier. — Mathematical demon- 

 stration and value of the angle of least deviation described by a 

 ray of light in its passage through a prism (one illustration), by 

 Giuseppe Vanni. — Practical determination of the metallic resist- 

 ance and chemical reaction of an electrolytic circuit, by Eugenio 

 Marchese. — On the causes of the remarkable after-glows wit- 

 nessed in Italy and elsewhere in 1883-84, by Prof. Carlo Maran- 

 goni. The author compares these phenomena with others of an 

 analogous character observed in various parts of Europe in the 

 year 1869. On several grounds he infers that the pink and red 

 glows could not have been produced by moisture disseminated in 

 the atmosphere in the solid, liquid, or gaseous state. He con- 

 cludes that they are due to the presence of dust or minute 

 particles of sand, which absorb the coloured rays in the central 

 region of the solar spectrum while transmitting the extreme 

 colours — that is, red and violet. The paper, which is to be con- 

 tinued, offers no suggestion as to the possible origin of the 

 particles of dust to which the phenomena are attributed. — Note 

 on the extinct and living mollusks of the Gardone district, by 

 Prof Strobel. — On the fossil insects of the Carboniferous schists 

 of Commentry, by S. Brongniart. — Note on the limits of dia- 

 tomaceous vegetation in marine basins, by Count A. F. 

 Castracane. 



Rendiconti del Reale Istilulo Lombardo, February 21. — Bio- 

 graphical notice of Carlo Tenca and his times, by Prof. Giovanni 

 Cantoni. — Some reflections on the results of the recent examina- 

 tions in the Italian language and literature in the higher schools 

 of the Peninsula, by Prof C. Baravalle. — Fresh researches on 

 the oxidation of sulphur, with some remarks on the oxidising 

 power of the so-called atomic oxygen and of ozone, by Prof. E. 

 Pollacci. — On some cases of subcutaneous nervous aftections 

 caused by the presence of Oscyuris, Taenia, Solium, and other 

 parasites, by Prof A. Scarenzio. — On the relations between the 

 malady known as " bronze skin," and the changes in the supra- 

 renal blood capsules, by Prof. G. Sangalli. — Meteorological 

 observations made in the Brera Observatory, Milan, during the 

 month of February 1884 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, March 27.— "On the Electro-chemical Equi- 

 valent of Silver, and on the Absolute Electromotive Force of 

 Clark Cells." By Lord Rayleigh, D.C.L., F.R.S. 



The investigations upon this subject which have been carried 

 on by Mrs. Sidgwick and myself during the last year and a half, 

 though not yet quite finished, are so far advanced that no doubt 

 remains as to the general character of the results ; and as these 

 results have application in the daily work of practical electricians, 

 it is thought desirable] to communicate them without further 

 delay. 



The currents are measured by balancing the attraction and 

 repulsion of coaxal coils against known veigh's, as described 

 before the British Association in 1882, a method which has fully 

 answered the favourable expectations then expressed. To what 

 was said on that occasion it will be sufficient for the present to 

 add that the readings are taken by reversal of the current in the 

 fixed coils, and the difference of weights thus found (abcut 1 

 grm.) represents the double force of attraction free from . rrors 

 depending upon the connections of the suspended coil, ai d other 

 sources of disturbance. 



The difficulties which have been experienced, and which have 

 been the cause of so much delay, have related entirely to th; 

 behaviour of the silver voltameters, of which never less than two, 

 and sometimes as many as five, have been included in the 

 circuit of the measured current. In order to render the deposit 

 more compact, and thus to diminish the danger of loss in the 

 subsequent manipulations, acetate of silver was added in the 

 earlier experiments to the standard solution of nitrate. Expe- 

 rience, however, has shown that the principal risk is not in the 

 loss of metal, but in the ob^tinate retention of salt within the 

 fine pores of the deposit, leading to an over-estimate of the 

 amount. When the texture is very compact, this danger in- 

 crea'es, and deposits from a solution containing acetate are often 

 decidedly too heavy, even after the most careful and protracted 

 washings. On heating to low redness a portion, at any rate, of 

 the retained salt is decomposed NO. 's driven off, and a loss of 



