622 



NA TURE 



[April 27, 1905 



nature : M. Jacoby. — Specimens of Papilio rnadeayana 

 and Hypocysta metirius captured in Queensland, illus- 

 trating the use of " directive " markings in the Rhopalo- 

 ccra in influencing their enemies to attack non-vital parts : 

 A. Bacot. — An example of Ccratoptcrus stahli, Wast., a 

 beetle from Australia possessing notable powers of crepi- 

 tation : G. J. Arrow. — A series of Erebia alccto {glacialis), 

 var. nicholli. Obth.. taken at about Sooo feet at Cam- 

 piglio. South Tyrol, with specimens of Dasydia tenebraria, 

 var. wochearia, caught in the company of the Erebias in 

 the same localities ; when upon the wing the two species 

 were not dissimilar : A. H. Jones and H. Rowland- 

 Brown. Mr. Jones also e.xhibited examples of Erebia 

 niclas from the Parnassus Mountains, Greece, for com- 

 parison, and fine forms of butterflies found at Mendel, near 

 Botzen. — -A series of Morplw adonis from British tiuiana, 

 with the very rare dimorphic black and white female : W. J. 

 Kaye. — The social web and pupal shells of Eiicheira 

 socialis, Westw., together with specimens of the perfect 

 insect, being the actual nest from Mexico described and 

 figured by Westwood in the Transactions for 1836 : Dr. 

 F. A. Dixey. After Dr. Dixcy had read a note upon the 

 habits of this and similar species, the Rev. W. T. Holland, 

 of Pittsburg, Pa., U.S..\., gave his personal experiences 

 of social silk-cocoon spinning species also from Mexico. 

 — A note recently received from Mr. S. A. Neave giving 

 further interesting evidence of the superstitious dread of 

 larvEB with terrifying eye-like markings entertained by 

 South -African natives : Prof. E. B. Poulton. — Experi- 

 ments to ascertain the vitality of pupfe subjected to sub- 

 mersion : F. Merrifleld. — Psetidacraea pogi;ci and Limnas 

 chrysippus ; the numerical proportion of mimic to model : 

 H. A. Byatt. — A monograph on the genus Ogyris : G. 

 Bethune-Baker. 



Geological Society, April 5.— Dr. J- E. Marr. F.R.S. 

 president, in the chair. — On the divisions and correlation 

 of the upper portion of the Coal-measures, with special 

 reference to their development in the midland counties of 

 England : R. Kidston. The following classification of 

 the Coal-measures is proposed by the author : — 



Proposed names 



(4) Radstockian Series 

 (3) StafTordian Series 

 (2) Westphalian Series 

 (i) Lanarkian Series 



Names previously use 

 Upper Coal-measures. 

 Transition Series. 

 Middle Coal-measures, 

 flower Coal-measurei 



(in- 



cluding the Millstone Grit). 



— On the age and relations of the phosphatic chalk of 

 Taplow : H. J. O. White and L. Treacher. The rocks 

 at the locality of Taplow are described in detail, and the 

 following classification is adopted : — (E) Upper White 

 Chalk (visible), 16 feet ; (D) Upper Brown Chalk, or rich 

 phosphatic band, about 8 feet : (C) Middle White Chalk, 

 about 16 feet ; (B) Lower Brown Chalk, or rich phosphatic 

 band, about 4 feet ; (A) Lower White Chalk (visible), 

 17 feet. Fossil-lists are given from each of the above 

 divisions, and the authors conclude that the Lower White 

 Chalk belongs to the zone of Micrastcr cor-anguinuni, and 

 the succeeding beds to that of Marstipites tcstudinarius ; 

 while the lower phosphate-band represents the lower part 

 of the Uintacrinus-band, and the upper one that of the 

 Marsupites-band of that zone. 



Physical Society, April 14.— Dr. R.T. Glazebrook, F.R.S. , 

 past-president, in the chair. — Ellipsoidal lenses : R. J. 

 Sowter. The paper extends the treatment of thin 

 ellipsoidal or astigmatic lenses, and gives a simple solution 

 for complex problems of the following types : — " To deter- 

 mine the astigmatic pencil, after refraction of an astig- 

 matic pencil by an ellipsoidal lens." And " to find the 

 ellipsoidal lens equivalent to two cylindrical lenses placed 

 a definite distance apart, with their axes inclined at any 

 angle." The method of treatment can be applied to 

 crossed ellipsoidal lenses, in contact, or separated, and is 

 applicable in general to astigmatic pencils. — Defermination 

 of the moment of inertia of the magnets used in the 

 measurement of the horizontal component of the earth's 

 field : Dr. W. Watson. One of the constants required 



NO. 1852, VOL. 71] 



when determining the horizontal component of the earth's 

 magnetic field by the ordinary method is the moment of 

 inertia of the magnet which is used in the vibration ex- 

 periment. It is usual to determine the moment of inertia 

 of the cylindrical brass bar supplied with each instrument 

 by calculation, then by measuring the period of the magnet 

 alone, and when loaded with this bar to calculate the 

 moment of inertia of the magnet. This method pre- 

 supposes that the density of the inertia-bar is uniform 

 throughout. It is not easy to secure a bar of which the 

 density is uniform throughout, and further it is difficult 

 to test whether such uniformity has been secured. The 

 author thinks that more trustworthy and uniform results 

 would be obtained by determining once for all, with very 

 great care, the moment of inertia of a standard bar and 

 then determining the moment of inertia of the bars sup- 

 plied with the different magnetometers, by comparing 

 them with the standard bar experimentally. In the paper 

 is described an instrument suitable for comparing the 

 moment of inertia of bars, together with some experiments 

 made with a view to determine the moment of inertia of 

 a standard bar, and an investigation of the influence of the 

 air upon the period. — Exhibition of a series of lecture ex- 

 periments illustrating the properties of the gaseous ions 

 produced by radium and other sources : Dr. W. Watson. 



Royal Astronomical Society, April 14 — Mr. W, II. Maw, 



president, in the chair. — Spherical aberration of object 

 glasses : A. E. Conrady. The paper dealt with the differ- 

 ence of phase at the focus caused by the spherical aberra- 

 tion. Two different rigorous solutions, by which such 

 differences could be conveniently computed, were deduced 

 and discussed. The paper also dealt with the relation 

 between these differences of phase and spherical aberration 

 in the geometrical sense. — (i) A suggested arrangement 

 for the mounting of a ccelostat ; (2) point distributions on 

 a sphere, with remarks on the determination of the ape.x 

 of the sun's motion : H. C. Plummer. — The four-prism 

 spectrograph attached to the Xewall telescope of the Cam- 

 bridge Observatory, with remarks on the general design 

 of spectrographs for equatorials of large aperture, con- 

 sidered from the point of view of " tremor-discs " : H. F. 

 Newall. 



Royal Meteorological Society, April 19. — Mr. Richard 

 Bentley, president, in the chair. — .An account of the observ- 

 ations at Crinan in 1904, and description of a new meteor- 

 ograph for use with kites : W. H. Dines. These observ- 

 ations, which are carried out under the direction of a 

 joint committee of the Royal Meteorological Society and 

 of the British Association, are made with meteorographs 

 attached to kites with the object of ascertaining the con- 

 ditions prevailing in the upper atmosphere. During last 

 summer the kites were flown from the deck of H.M.S. 

 Seahorse, which was placed at the disposal of the com- 

 mittee by the Admiralty. Mr. Dines designed a new and 

 inexpensive meteorograph, which he now fully described. 

 The weather conditions of last summer were somewhat 

 unusual, there being a decided preponderance of east and 

 south-east winds. Near the summit of Ben Nevis the air 

 was often dry, and was on several occasions warmer than 

 the air at the same level at Crinan. As a rule, however, 

 the temperature on Ben Nevis is generally much lower 

 than the temperature in the free air at the same level. 

 On several occasions temperature inversions were observed 

 at levels between 3000 feet and 7000 feet. A fact previously 

 noticed was again observed, viz. the decrease of strength 

 of easterly winds with elevation. — Rate of fall of rain at 

 Seathwaite : Dr. H. R. Mill. This is a discussion of the 

 records from a Negretti and Zambra self-recording rain 

 gauge during a period of eighteen months. Seathwaite, 

 which is in Borrowdale, Cumberland, is in almost the 

 wettest spot of the British Isles, the average yearly rainfall 

 being about 137 inches. Dr. Mill's results seem to show 

 that the rainfall at Seathwaite in an average year indicates 

 a tendency to be greater during the hours of darkness than 

 in daylight, that rather less than half the time during 

 which rain is falling it continues without intermission for 

 at least six hours at a time, and that rather more than 

 half the total amount of rain is deposited in such long 

 showers. 



