Dec. 6. 188 -J 



NA TURE 



143 



inches wider and deeper than the old screen. It has also an 

 upper sloping roof, and, at a little distance below, a flat, inner 

 roof pierced with holes for ventilation ; while the old screen has 

 a single flat roof with only a narrow slit beneath on each side for 

 ventilation. Observations were made during the three months 

 July to .Septemlier, and the results are given in the paper. From 

 these it appears that (he new screen is, of the two, sli.tjhtly 

 cooler and better ventilated, and retains the heat of the sun for 

 a less time than the old screen ; also, having a double roof and 

 overlapping boards bel )w, it is bettter suited for extreme cli- 

 mates. — On the storm which crossed the British Isle> between 

 September I and 3, 18S3, and its track over the North Atlantic, 

 by_C. Harding, F.R.Met.Soc, of the Meteorological Office. 

 This storm caused considerable havoc in the south-west and 

 south of England, owing not only to its exceptional violence, 

 but also to its occurrence before the completion of the harvest. 

 The storm is traceable, in the fir>t instance, to two centres of 

 disturbance, one being first shown at about 450 miles to the 

 south of Bermuda on August 26, and the other to the east of 

 the Rocky Mountains on the 27th ; these two disturbances after- 

 wards merged on the 29tli, at about 300 miles to the nortli of 

 Bermuda, and formed one great and destructive gale, which 

 continued to grow in violence as it crossed the Atlantic until it 

 reached the coasts of the British Islands. The average speed at 

 which this storm crossed the Atlantic was fully forty miles an 

 hour, which is mire than double the usual speed of storms which 

 traverse that ocean. — On the influence of the moon on the height 

 of the barometer within the tropics, by Robert Lawson, Inspec- 

 tor-General of Hospitals. — The great ice-storm of July 3, 1S83, 

 in North Lincolnshire, by J. Cordeaux. The direction of the 

 storm was nearly south-east to north-west, and travelled from 

 Caistor along the higher ridges of the hills to Barton-on Humber. 

 The storm commenced at about 9.20 p.m. with heavy drops of 

 rain, and increased to a downpour, speeddy followed, amidst 

 the blaze of lightning at.d the constant roll of thunder, by the 

 rush of hail, or rather lumps of ice. An eye witness remarked 

 that they were not like hadstones, but "salt-cellars"; another 

 that they resembled "ducks' eggs"; in fact 'hey were solid lumps 

 of ice of every shape and size, weighing from two to six ounces, 

 and some were measured six inches in circumference. The 

 injur)' done to the growing crops cannot be estimated at less than 

 20,000/. 



Physical Society, November 24. — Prof. R. B. Clifton in 

 the chair.— Prof. Reinold read a paper by Mr. J. W. Clark, on 

 the purilicition of mercury by distillation in vacuo. The advan- 

 tages of Mr. Clark's apparatus are— the small quantity of mercury 

 in use at a time, and the fact that no auxiliary Sprengel pump 

 is required. This is avoided by having a movable reservoir of 

 mercury, on raising which the distiller is filled with mercury. 

 The apparatus was described in detail, and illustrated by a 

 figure. It is probable that zinc, cadmium, magnesium, &c., 

 may be distilled and thus purified by the same apparatus. — Mr. 

 A. P. Chattock then read a paper on a method of determining 

 experimentally the constant of an electrodynamometer. In ex- 

 isting methods it is necessary to measure the areas of the coils, 

 which is a difficult matter to do with a finished instrument ; by 

 the new method this is unnecessary. It depends on the accurate 

 determination of the speed of the movable coil. Mr. Chattock 

 exhibited an instrument whose constant had been determined by 

 him in the laboratory of Prof. Foster, University College, with 

 the assistance of Mr. Grant.— Prof. G. C. Foster then took the 

 chair, and Prof. R. B. Clifton, president, read a paper on the 

 measurement of the curvature of lenses. With very small 

 lenses the spherometer cannot be used, and the author's 

 method is based on the Newton's rings formed between the 

 lens and a plane surface, or a curved surface of known 

 radius. From the wave-length of the light employed in 

 ob.serving, and the diameter of a ring, the radius of curvature 

 can be determined. He places the lens on a plane or curved 

 surface under a microscope, and lights it by the sodium flame 

 (wave-length 5892X10-?); he measures the approxmia^e dia- 

 meters of two rings a distance apart (in practice the tenth and 

 twentieth rings are found convenient), takes the difference of 

 their squares, and divides it by the wave-length, and the number 

 of rings in the gap between to find the radius of the lens. The 

 formula is — 



p' m A = ^-f 



-:) 



where x„, _^ „ and x„ are the diameters of the Hth and [m -1- «)th 



rings ; K is the wave-length of the light, and p^ the radius of 

 curvature of the lens. The method with proper cire gives 

 accurate results. Prof. Clifton has also used it to determine the 

 refractive index of liquids in small quantities ; Mr. Richardson 

 having found it for water = i -3335 by this method, which is 

 usually correct to two places of decimals. It can also be used 

 to determine if the lens is uniformly curved and spherical. Prof. 

 Perry suggested that it might be also used to measure a surface 

 without touching it, say the surface of a w.ater drop, or a strip of 

 glass when bent. In this way it might throw light on the laws 

 of capillarity or bending. 



Manchester 



Literary and Philosophical Society, October 2.— H. E. 

 Roscoe, F. R.S., president, in the chair. — On the change pro- 

 duced in the motion of an oscillating rod by a heavy ring sur- 

 rounding it, and attached to it by elastic cords, by James 

 Bottomley, F.C.S. 



October 16.— H. E. Roscoe, F.R.S., president, in the chair. 

 —On the leaves of Catha edulis, by C. Schorlemmer, F.R.S.— 

 Dr. Schuster, F.R..S., gave an account of meteoric dust, and 

 exhibited some specimens found in Himalayan snow. — On the 

 duality of physical forces, by James Rhodes, M.R.C.S. 



October 30.— J. P. Joule, F.R.S., vice-president, in the chair. 

 — On the action of water upon beds of rock salt, by Thomas 

 Ward. 



Cambridge 



Philosophical Society, October 29. — On the structure of 

 the cells of secretory glands, by Mr. J. W. Langley. — Note on 

 the fibrin-ferment, by Messrs. A. S. Lea and J. K. Green. — On 

 the structure of the epidermis of the ice-plant [Mesembryanthe- 

 mum crystallinum), by Mr. M. C. Potter. — On the physiological 

 significance of water-glands, by Mr. Walter Gardiner. 



Paris 

 Academy of Sciences, November 26. — M. Blanchard, 

 president, in the chair. — On the treatment of plague-stricken 

 swine by vaccination w ith the fatal virus itself in an attenuated 

 form, by M. Pasteur and the late M Thuillier. — On the hydra- 

 tation of crotonic aldehyde, by M. Ad. Wurtz. — Propagation 

 across the Indian and Atlantic Oceans of the great earthquake 

 wave caused by the recent disturbances at Java, by M. de Lesseps. 

 From the observations taken at Colon by the engineers engaged on 

 the Panama Interoceanic Canal, the wave v\ould appear to have 

 made its way in about thirty hours from Java, round the Cape 

 of Good Hope to the east coast of Central America. — Theoretical 

 considerations on the action of floats kept in tow at divergent 

 angles, by M. E. de Jonquieres. — On the secular variation in 

 the direction of the terrestrial magnetic force at Paris, by M. L. 

 Descroix. — On the successive parthenogenetic reproduction of 

 phylloxera for nine generations, and on the results obtained by 

 various methods of treatment of vines attacked by phydoxera 

 made by M. P. Boiteau. — Observations of the planets 233 and 234 

 at the Paris Observatory (equatorial of the west tower), by M. 

 G. Bigourdan. — On a formula of M. Tisserand connected by the 

 celestial mechanism, by M. O. Callandreau. — On the algebraic 

 integration of linear equations, by M. H. Poincare. — On an in- 

 duction magnetic needle, by M. Mascart. — On the electric .syn- 

 chronism of two relative movements, and its application to the 

 construction of a new electric compass, by M. Marcel Deprez. — 

 A study of earth currents, by M. E. E. Blavier. — Measurement 

 of the differences of potential of electric layers on the surface of 

 two liquids in contact (four illustrati jus), by MM. E. Bichat 

 and R. Blondlot. — Wave-lengths of the optical rays A .and a, 

 by M. W. de W. Abney. — Description of a micro hermometer 

 f^r gauging very slight viriations of temperature, by M. F. 

 Larroque. — -Studies on the chemical action of light ; decomposi- 

 tion of oxalic acid by the perchloride of iron (three illustrations), 

 by M. G. Lemoine. — Dissociation of the anhydrous carbonate 

 of ammonia caused by excess in one or other of its elements, by 

 M, Isambert. — On the fusibility of salts ; nitrates, by M. E. 

 Alaumene. — On hydronicotine and oxytrinicotine, by M. A. 

 Etard. — On the relative velocity of the sensations of sight, 

 hearing, and touch, by M. A. Bloch. This paper consists of 

 three distinct parts, each dealing with the comparison of two 

 sensations— (l) hearing and touch ; (2) hearing and sight ; (3) 

 sight and touch. The author concludes thai ol the three sensa- 

 tions sight is the most rapid ; then hearing, the transmission of 

 which sensation lasts 1/72 of a second longer than that of 



