December 4, 1902] 



NA TURE 



119 



tinent. None of the objects found with the remaining fourteen 

 interments are of later date than the thin, flat, broad knife- 

 dagger. As no other ceramic type in Britain can show such a 

 pedigree,it is clear that the beaker is the oldest, though before 

 it died out several other types of fictilia came into use. 



Royal Meteorological Society, November 19.— Mr. 

 W. H. Dines, president, in the chair. — Mr. F. Campbell 

 Bayard read a paper on English climatology, 1881-1900, which 

 was a discussion of the climatological data printed in the 

 Meteorological Record from the forty stations of the Royal 

 Meteorological Society, which have been continuous for the 

 whole of the twenty years. The elements dealt with by the 

 author are: — (1) temperature at 9 a.m.; (2) mean minimum 

 temperature ; (3) mean maximum temperature ; (4) relative 

 humidity ; (5) amount of cloud ; (6) rainfall ; and (7) number of 

 rainy days. The results form a valuable contribution to the 

 climatology of the British Isles. — A paper by Mr. C. V. 

 Bellamy, on the rainfall of Dominica, was also read. This was 

 in continuation of a former paper on the subject, and dealt 

 with all the available rainfall data for the Island of Dominica. 

 From this it appears that the mean annual rainfall of the island 

 is 1 10 inches. In the neighbouring island of Montserrat, a re- 

 markably heavy rainfall occurred during the night of November 

 28-29, '896, when as much as 2013 inches fell in the space of 

 six or eight hours. 



Cambridge. 



Philosophical Society, November 10.— Dr. Baker, presi- 

 dent, in the chair. — Notes on a vibration magnetometer, and on 

 the ball-ended magnets of Robison, by Mr. G. F. C. Searle. 

 The comparison of the horizontal components of magnetic fields 

 by the method of vibrations presents no difficulty when each 

 field is so nearly uniform that a vibrating magnet several centi- 

 metres in length may be used. But when the fields are far 

 from being uniform, the magnet must be quite short. The 

 magnet must in any case be slender, for unless its length be at 

 least ten times its diameter, the magnetic moment varies appre- 

 ciably when the field varies, even for fields comparable with 

 that of the earth. A simple magnet I "J cm. in length and 

 o'I5 cm. in diameter is in many ways practically inefficient. In 

 the vibration magnetometer exhibited to the Society, the magnet 

 is I '5 cm. in length and o'i5 cm. in diameter. The time of 

 vibration is increased from 1*4 to 6-3 seconds by attaching the 

 magnet to a pointed plumb-bob the mass of which is about fifty 

 times greater than that of the magnet. The bob also carries an 

 aluminium pointer to magnify the motion ; this enables the 

 time of vibration to be very exactly determined. Ball-ended 

 magnets were devised by Prof. John Robison, of Edinburgh, 

 about 1770 ; the author was led, independently, to the same 

 design. — On cavitation in liquids, and its occurrence in lubrica- 

 tion, by Mr. S. Skinner. If water is run into the space between 

 two lenses, arranged so as to show Newton's rings, and if one 

 of the lenses is rolled on the other, a crescent-shaped cavity is 

 developed when the velocity of rolling exceeds a certain critical 

 value. The cavity fills as soon as the rolling ceases. With 

 more viscous liquids, such as lubricating oils or glycerine, the 

 formation of the cavity is more marked. With colourless liquids, 

 the production of the cavity is observed by taking advantage of 

 total internal reflection or by using sodium light and observing 

 the Newtonian rings formed in the cavity. With deeply 

 coloured liquids, the effect may be observed by transmitted 

 light. Instantaneous photographs have been obtained of the 

 effects with lenses rolling on planes, lenses sliding on planes and 

 in some other cases. The effects are shown to agree with 

 Osborne Reynolds's theory of the viscous origin of friction when 

 copiously lubricated surfaces move over one another (Phil. 

 Trans. A, 1S86). That the maximum negative pressure occurs at 

 some distance from the point of nearest approach is confirmed by 

 these observations, and it appears that the layer of lubricant 

 which separates the surfaces at the point of nearest approach is 

 thinner than the wave-length of sodium light. Cavities of the same 

 character probably occur in all sufficiently lubricated bearings. — 

 On the coral reefs of Pemba Island and British East Africa, by 

 Mr. C. Crossland. The paper shows that the island of Pemba, 

 though very similar in structure to that of Zanzibar, is of separate 

 origin to the mainland, whereas the latter island is a part of the 

 mainland barrier system. The fringing reef of the east coast of 

 Pemba represents an early stage in the formation of that of 

 Zanzibar, while a barrier reef, also a result of erosion, not of 

 growth, encloses large bays on the west coast which are com- 



NO. 1727, VOL. 67] 



parable to the lagoon of the Bermuda atoll. The mainland of 

 East Africa is bordered by both fringing and barrier reefs, both 

 of which are formed entirely of dead rock, in which physical 

 agencies have in some cases produced miniature atolls. Wherever 

 growing coral occurs in the East African region, it is seen that 

 the physical conditions (e.g. the absence of big waves) are 

 not such as to allow the formation of typical reefs. Finally, 

 some observations on the conditions favourable to coral growth 

 were given, which conditions are present round an oceanic atoll 

 to a much greater degree than near a continental area. — On the 

 theory of aggregates, by Mr. A. N. Whitehead. 



Paris. 

 Academy of Sciences, November 24. — M. Albert Gaudry 

 in the chair. — The velocity of light and the solar parallax, by 

 M. Perrotin. An account of experiments at the Observatory of 

 Nice on the velocity of light. Fizeau's method was used, the 

 total distance traversed by the light being 92 kilometres. As 

 the emission telescope, the 72 cm. objective of the Observatory 

 was utilised, with a 38 cm. objective as collimator. The mean 

 result of 1 109 observations was 299,860 kilometres per second 

 in a vacuum. By combining this with the observations on the 

 planet Eros, from which a value of 8" '805 was deduced for the 

 solar parallax, the coefficient of annual aberration was found to 

 be 20"'465, the exact number adopted by the International 

 Astronomical Conference of 1S96 at the instance of MM. Lcewy 

 and Newcomb. — On the origin and geographical dispersion of 

 Lagoi?:ys corsica/ius, by M. Ch. Deperet.— Report en the work 

 accomplished by the Brazilian Commission, under the direction 

 of M. Cruls, on the exploration of the principal sources of the 

 Javary, and for the determination of the geographical co- 

 ordinates of several points in this region at points common to 

 Peru, Brazil and Bolivia, by M. Lcewy. — Observations of the 

 sun made at the Observatory of Lyons with the Brunner 16 cm. 

 equatorial during the third quarter of 1902, by M. J. Guillaume. 

 Tables are given showing the number of spots, their distribution 

 in latitude and the distribution of the faculze in latitude. — On 

 monodrome functions with an isolated essential singular point, 

 by M. Edmond Maillet. — On an extension of the notion of 

 periodicity, by M. E. Esclangon. — On an automatic carburettor 

 for explosion motors, by M. A. Krebs. A theoretical investiga- 

 tion as to the manner in which the area of the orifice air should 

 vary with the pressure of the air and the height of the 

 petrol in the reservoir. Following the indications thus 

 obtained, an apparatus has been constructed in which 

 these conditions are fulfilled, and it has been found that 

 the velocity of the motor can be varied suddenly between very 

 wide limits, an absolutely constant gas mixture being obtained. 

 ■ — On the construction of electrodiapasons with long variable 

 periods, by M. E. Mercadier. — On the ionisation of a salt 

 flame, by M. Georges Moreau. The ionisation of the salt flame 

 was found to decrease according to an exponential function of the 

 distance between the electrodes, and the conclusion is drawn 

 that the unipolar conductivity of a saline vapour is analogous 

 to that of a mass of hydrogen surrounding an incandescent 

 carbon filament, or that of a gaseous mass in contact with a 

 metal illuminated by ultra-violet radiations. — Some observations 

 on uranous oxide, by M. Qichsner de Coninck. Uranyl brom- 

 ide, ignited in a current of air, loses its bromine, thus 

 differing from the behaviour of the corresponding chloride. 

 — On the combinations of the complex cyanides with 

 fatty amines, by M. P. Chretien. A study of the salts obtained 

 by the action of hydroferrocyanic acid upon the primary iso- 

 amylamines. — A method for the estimation of glycerol in wine, 

 by M. A. Trillat. The method is based upon the solvent powers 

 of pure acetic ether for glycerol. The glycerol extracted is much 

 purer than that obtained by the usual alcohol-ether method. — 

 On the structure of the muscles of Anomia ephippium, by M. 

 Jobert.— On some new or slightly known forms of Rhabditis, by 

 M. Aug. Michel.— The theory of phytons in Gymnosperms, by 

 M. G. Chauveaud. — On the mode of vegetation and reproduction 

 of Amylomyces Rouxii, the fungus of Chinese yeast, by 

 M. J. Turquet. — The actual production of native sulphur in the 

 subsoil of the Place de la Republique, in Paris, by M. Stanisla, 

 Meunier. In the course of the excavations for a railway tunnels 

 native crystallised sulphur has been found in a black clay. 

 Reasons are given for supposing that this deposit has been 

 formed during the last two centuries.— On the general theory of 

 the action of some diastases, by M. Victor Henri. Two hypo- 

 theses are examined ; supposing that a portion of the ferment 



