i88 



NATURE 



[May 27, 1Q09 



African records from the year 1841 to 1906. He found 

 that the indications of a cyclical oscillation of the belt to 

 and from the equator over South Africa were strong 

 enough to encourage the belief that an analysis of 

 Australian records on the one side, and of Argentine on 

 the other, would prove that all the action centres of the 

 atmosphere were moving together over this wide area, 

 and that a similar oscillation existed in the northern hemi- 

 sphere. He subsequently found that investigations of Mr. 

 H. C. Russell and Dr. W. J. S. Lockyer supported his 

 conclusion that there is a period of about 95 years between 

 the greatest north and greatest south position of the anti- 

 cyclonic belt in the southern hemisphere, the double 

 oscillation thus talcing nineteen years. He has since ex- 

 tended the inquiry into the movements of the action-centres 

 in the northern hemisphere with the view of ascertaining 

 whether they show any similar oscillation to and from the 

 equator, which is not to be explained by seasonal changes 

 of position. Dealing with the Nile floods, he draws the 

 inference that the high-pressure systems which affect North- 

 east Africa are farther north when the floods are in excess 

 and nearer to Egypt when they are deficient. He also 

 made an analysis of the tracks of the hurricanes which 

 passed north and south of Manila Observatory, and found 

 that these throw an interesting light upon the oscillations 

 of the action-centres of the atmosphere. — Errors of estima- 

 tion in thermometric observations : h. Walter. In 

 examining the returns from a newly inaugurated series of 

 second-order meteorological stations in Mauritius, it was 

 noticed that a large percentage of the thermometer read- 

 ings was in whole or half divisions. This led the author 

 to analyse the returns, and he gave in the paper the 

 frequency curves of the " tenths of estimation." 



Institution of Mining and Metallurgy, May 20. — Mr. 

 Edgar Taylor, president, in the chair. — Notes on the 

 Zangezour copper mines : Dr. A. L. Simon. A brief 

 description of the geology, mines, and mining conditions 

 and costs of mining, reduction and production of copper 

 in this district of the Little Caucasus. — The determination 

 of tungstic acid in low-grade wolfram ores : H. W. 

 Hutchin and F. J. Tonks. .'\ description of a new 

 method introduced by the authors, for which it is claimed 

 that it combines the accuracy of the mercurous nitrate 

 method with an improvement in the attack of the mineral, 

 fusion with alkalis being replaced by digestion with caustic 

 soda solution. The preliminary treatment with hydro- 

 fluoric acid becomes unnecessary, and the charge of ore 

 can be much larger than is customary. The paper consists 

 of two parts, section i. dealing with the working details 

 of the assays employed, with a tabulation of results for 

 comparison, whilst section ii. is supplementary, and 

 consists mainly of an investigation of conditions affecting 

 the aqua regia method and that here brought to notice. — 

 Cupellation experiments ; the thermal properties of cupels : 

 C. O. Bannister and W. N. Stanley. The authors here 

 record a series of careful experiments made for the purpose 

 of comparing patent cupels (i.e. cupels made with a 

 magnesite base) with bone-ash cupels, as regards their 

 relative diffusivitv of heat, specific heat, and rate of cool- 

 ing, &-c., and the result of their tests was to establish 

 the existence of great differences in the thermal properties 

 of the two classes of cupel mentioned, notably as follows : — 

 the difTusivity of heat and specific heat of patent cupels 

 are greater, and the actual temperature of the cupelling 

 button is much lower, at the same temperature of muffle, 

 in patent cupels than in those made of bone-ash, and silver 

 beads take longer to solidify and spit, and are, indeed, 

 much less likely to spit, on patent than on bone-ash cupels. 

 — The bessemerising of hardhead : D. M. Levy and D. 

 Ewien. The authors found, in the course of researches 

 conducted to that end, that it is possible by bessemerising 

 to convert hardhead, which is one of the waste products 

 of tin smelting, into a highly ferruginous slag, and a fume 

 consisting to a large extent of arsenic oxide with some 

 tin oxide, whilst nickel and cobalt gradually concentrate in 

 the diminishing button. The heat evolved by the operation 

 IS sufficient to keep the products molten and the process 

 self-supporting. It remains to be ascertained, however, 

 whether the slags can be obtained of sufficiently low tin 

 contents to make the process a commercial success. — The 

 NO. 2065, VOL. 80] 



use of standards in reading gold pannings ; S. J. Lett. 

 Having procured for his own use weighed standards of 

 gold dust for comparison when reading pannings, the 

 author submitted a description of these for the benefit of 

 others requiring a handy and portable apparatus by means 

 of which it is, the author claims, possible to gauge 

 accurately a much smaller quantity than i dwt. — Notes 

 on the scaling and sweating of copper battery plates : 

 S. F. Goddard. This is a brief account of the results 

 of cleaning two copper plates after fifty months' running, 

 during which period 33,000 tons of quartz ore were crushed. 

 It was found subsequently, by melting the plates, that only 

 an exceedingly small percentage of gold was actually 

 absorbed by the copper, and that only in the upper 

 portion. 



Manchester. 

 Literary and Philosophical Society. Mav 4 — Mr. F. 

 Jones, president, in the chair. — The tent-building habits of 

 the ant Lasius niger, Linn., in Japan : Dr. Marie Stopes 

 and C. G. Hewitt. The species of ant constructing the 

 nests, which were cylindrical in shape, is Lasius niger, 

 the common brownish-black ant occurring in our English 

 gardens. In this particular district of Hayama, within 

 fifty miles of Tokyo, it constructs shelters of minute grains 

 of sand cemented together on the twigs of the Ilex as 

 axes. The object of these nests is to afford shelter for 

 aphides or " plant-bugs " which live upon the plant and 

 are looked after by the ants for the sake of the " honey- 

 dew " which they secrete. The shelters not only keep the 

 aphides warm, and so increase their yield of " honey- 

 dew," but also prevent them from escaping and protect 

 them from their enemies and other ants. For their own 

 convenience the ants also construct covered galleries of 

 the sand detritus, which wind round the trunk of the tree 

 and communicate with the tents in which the aphides are 

 confined and with their own nest on the ground. This is 

 the only case described of L. niger, which has a world-wide 

 distribution, constructing tents of this kind. — ^The per- 

 manent change of volume effected in cast irons bv repeated 

 heatings: Prof. H. F. Rugran and Prof. H. C. H. 

 Carpenter. 



Dublin. 

 Royal Dublin Society, April 20. — Mr. J. E. Gore in 

 the chair. — Mechanical stress and magnetisation of iron : 

 W. Brown. Results have been obtained with iron wires 

 in a perfectly uniform magnetic field throughout their 

 entire length by varying the magnetic field, the load, 

 the size of wire, and the magnitude of the current through 

 the wire. — Methods of determining the amount of light 

 irregularly reflected from rough surfaces : Prof. W. F. 

 Barrett. The amount of light irregularly reflected from 

 rough surfaces is a matter of considerable practical 

 importance, especially in the case of large surfaces, such 

 as walls and buildings, but no satisfactory data appear 

 to be obtainable. The law of inverse square being in- 

 applicable to such surfaces, the author has employed two 

 methods, which yield satisfactory results. A Lummer- 

 Brodhun or other similar type of photometer is employed, 

 and the intensity of the stronger light reduced by (i) a 

 rapidly revolving opaque disc having a sector cut out, the 

 size of which can be accurately adjusted until a photo- 

 metric balance is obtained, or (2) by an adaptation of the 

 author's instrument for determining the " light-thresh- 

 hold " of the eye. In this case the stronger light is re- 

 duced by absorption through a column of liquid of neutral 

 tint, the length of the column being capable of easy and 

 accurate adjustment. By this means measurements can 

 be made of the light diffused at various angles from small 

 surfaces, which are used to replace the silvered mirror that 

 reflects the standard light through the liquid column. 

 This arrangement also affords a convenient method of 

 testing different systems of lighthouse illuminants. — A new 

 form of polarimeter for the measurement of the indices 

 of refraction of opaque bodies : Prof. W. F. Barrett. 

 By means of Brewster's law the index of refraction of 

 opaque non-metallic bodies can be found if the angle of 

 maximum polarisation by reflection can de determined. In 

 the instrument devised by the author this angle is ex- 

 peditiously found by causing the telescope, which projects 

 a parallel incident bcniii on to the reflecting surface, and 



