2 08 



NAT URE 



\_Dec. 27, I < 



(Trinity College, Dublin), Exhlbitio:i of 32/. a year [Mathe 

 matics and Physics]. 



For Hebrew: G. C. Ewing (Merchmt Taylors' School, 

 London), Exhibition of 33/. bs. %d. a year. 



SOCIETIES AND ACADEMIES 



London 



Royal Meteorological Society, December 19. — Mr. J. K. 



laughton, M.A., F.K.A.S., president, in the chair. — The fol- 

 lowing were elected Fellows: — K. Benilev, \V. Bonalin, Miss 

 E. Brooke, Rev. A. Conder, T. W. Cowl, J. A. \V. Oliver, 

 C. M. Powell, W. B. Tripp, and Fung Yee. The papers read 

 were: — On the 'explanation of certain weather prognostics, by 

 tlie Hon. Ralph Abercromby. The author explains abcut forty- 

 f ur well-known prognostics belonging to the following groups 

 — (I) diurnal ; (2) sun, moon, and stars ; (3) sky ; (4) rain, snow, 

 and hail ; and (5) wells, springs, and coal minCo — by referring 

 Ihem to the isobaric conditions in which they are ob.'erved. By 

 this means he is able to indicate the circumstances under which 

 any prognostic fails, as well as those under which it succeeds. — 

 Preliminary inquiry into the causes of the variations in the read- 

 ing of hlack-bulh thermometers in facno, by G. M. Whipple, 

 B.Sc. It has long been known th.it there is a want of accordance 

 between the different instruments u^ed for measuring the intensity 

 cf radiation, and with a view of ascertaining the cause of the 

 variations in the readings of the black-bulb thermometers in 

 vacuo, the author has made a comparison with a number of these 

 thermometers, the results of which are given in the paper. It is 

 shown di-tinctly that the effect of an increased coa'ing of lamp- 

 black on the bulb is to raise the temperature, and also that the 

 size of the thermomater-bulb is a most important factor in the 

 case of this instrument — Report on the phenological obser/a- 

 tions for 18S3, by the Rev. T. A. Preston, M. A.— Mr. J. S. 

 Dyason exhibited a series of coloured sketches illustrating the 

 rec;nt atmospheric phenomena during November and December. 



Geological Society, December 5. — J. W. Hulke, F.R.S., 

 president, in the chair. — George Jonathan Binns, Horace T. 

 Brown, James Dairon, Rodolph De Salis, Hu.;h Exton, John 

 Forrest, Prof. Bernard J. Harrington, J.ames Patrick Howley, 

 John Sylvester Hughes, Prof. George T. Kennedy, Rev. Arthur 

 Noel Malan, Robert Sydney Milles, Edwin Radford, Edward 

 Pierson Ramsay, William Henry Rands, Thomas Roberts, 

 Joseph Ridgvvay, and Harry Page Woodward we'e elected 

 Fellows of the Society. — On the Cambrian conglomer.ites resting 

 upon and in the vicinity of some pre-Cambrian Rocks (the so- 

 called intrusive masses) in Anglesey and Carnarvonshire, by 

 Henry Hicks, M.D., F.G.S. In a former paper the author had 

 maintained that there was no evidence to show that the so-called 

 intrusive granite in Anglesey had altered the Cambrian and 

 Silurian rocks in its immediate vicinity, or that they h.id been 

 entangled in it as described, but that it seemed to be a rock of 

 metamorphic origin, varying much in its general apiearance at 

 different points. He contended that, instead of being an in- 

 trusive granite, as .supposed by the officers of the Survey, it was 

 in all probability the oldest rock in Anglesey. The basal Cam- 

 brian conglomerate in contact with it is in an unaltered condi- 

 tion, and at Llanfaelog contains an extraordinary proportion of 

 well-rolled pebbles, identical in mineral composition with the 

 so-called granite immediately below. Fragments of all the 

 varieties of rock found in the granitoid axis are recognisable in 

 the conglomerate, and in precisely the same condition as in the 

 parent rock. Fragments of the various schists of the area were 

 also present ; so that he thought there cannot be the shadow of 

 a doubt that the so-called granite and the met,amorphic schists 

 are older than the conglomerate, and therefore pre-Cambrian. 

 The view maintained by the Survey that the schists are altered 

 Cambrian and Silurian strata, and the granitoid rock an intrusive 

 granite of Lov\er Silurian age, is consequently quite untenable. 

 In Carnarvonshire equally conclusive evidence was obtained 

 from many areas. Fragments of the Dimetian (Twt Hill type) 

 occurred abundantly in the basal Cambrian conglomerates at 

 Dinas Dinorwig, Pont Rothel, Moel Tryfane, and Glyn Llifon. 

 Quartz-felsite pebbles in every respect identical with the varieties 

 found in the so-called intrusive ridges between Bangor and 

 Carnarvon, and to the north and south of Llyn Padarn, were 

 found on the shores of the Menai Straits, in the railway-cutting 

 at Bangor, at Liandeiniolen, Dinas Dinorwig, Llyn Padarn, and 



^Isewhere. This evidence, supplementary to that previously 

 furnished by Prof. Huglies, Prof. Bonney, and the author, is 

 conclusive as to these areas, since the basal Cambrian con- 

 glomerates, which are in contact with these supposed intrusive 

 m.asses, are composed .almost entirely of rocks identical with the 

 latter ; and this could not pos-ibly be the case if the granitoid 

 masses had been intruded among the conglomerates after their 

 deposition. — On some rock-specimens collected by Dr. Hicks in 

 Anglesey and North- West Carnarvonshire, by Prof. T. G. 

 Bonney, F.R.S., Sec.G.S. The author stated that pebbles in 

 the blocks of conglomerate collected by Dr. Hicks to the north 

 of Llanfaelog were practically undistinguishable macroscopically 

 and microscopically from the granitoid and gneissic rocks which 

 occur ill siiii between that place and Ty Croes, and that the 

 matrix contained smaller fragments, probably from the same 

 rock, with schist bearing a general resemblance to members of 

 the group of schists so largely developed in Anglesey, and with 

 grits, .argillites, &c. Pebbles of granitoid aspect in the Cam- 

 l>r:an conglomerate near Dinas Dinorwig, ktc, bear a very cbi^e 

 resemblance to the Twt Hill rock, and are associated with 

 abundant rolled fragments of rhyolite resembling those already 

 described from the Cambrian conglomerate and the underlying 

 conglomeratic beds and rhyolites. Two pebbles of rather 

 granitoid aspect in the Cambrian conglomerate by the shore of 

 the Menai Straits, near Garth, prove to be spherulitic felsite, 

 .somewhat resembling that already described by the author from 

 Tan-y-maes. He pointed rut that the evidence of these speci- 

 mens collected by Dr. Hicks, added to that already obtained, 

 led irre-i>tibly to one of two conclusions — either that, when the 

 Cambrian was formed, an area of very ancient metamorphic 

 rock was exposed near Ty Croes and in the Carnarvonshire 

 district, or that the rhyolitic volcanoes were so much older than 

 the Cambrian time that their granitic cores were already laid 

 bare by denud.ation. Hence, in either case, the existence of 

 Archaean rock in North Wales was proved. To one or other of 

 these conclusions he could see no po-sible alternative, and he 

 considered the former to be (even if some of the granitoid rock 

 were granite) far the most probable. — On some post-Glacial 

 ravines in the Chalk Wolds of Lincolnshire, by A. J. Jukes- 

 Browne, F.G.S. 



Edinhurgh 

 Mathematical Society, December 14. — Mr. Thomas Muir, 

 pre-ident, in the chair. — Mr. J. S. Mack.ay read a paper on the 

 medioscribed circle of a triangle with its analogous and asso- 

 ciated circles viewed from their centres of similitude. — Prof. 

 Chrystal stated some propositions in geometry for which he wished 

 proofs. — Mr. Muir made a communication on determinants with 

 /-termed elements. — The Secretary gave a new construction by 

 the Rev. G. McArthur for Euclid ii. 9, 10; and Mr. James 

 Taylor Dollar proposed for solution a theorem in elementally 

 geometry. 



CONTENTS Page 



Vortex Rings. By Prof. Osborne Reynolds, F.R.S. 193 

 Our Book Shelf:— 



Brezina's " Krystallographische Untei'suchungen an 



homologen und isomeren Reihen" 195 



Letters to the Editor : — 



The Remarkable .Sunsets. — D. Pidgeon ; Hon. 



F. A. R. Russell ; Prof. Lewis Campbell . . 195 

 Peripniu-.— Prof. H. N. Moseley, F.R.S., and 



A. Sedgwick 196 



A New Rock.— Dr. Karl Pettersen 196 



Diffusi m of .Scientific Memoirs. — W. M. Hicks; 



Prof. P. G. Tait 196 



The " Talisman " Expedition. By Prof. Alphonse 



Milne-Edwards 197 



Music and Science. By Dr. W. H. Stone .... 198 

 The Remarkable Sunsets. P>y Edward Whymper . 199 



Notes 200 



International Polar Observatories. By Robert H. 



Scott, F.RS., and Dr. Wild 201 



Movements of the Earth, III. By J. Norman 



Lockyer, F.R.S. ^IVith lUuslrations) 201 



Probable Nature of the Internal Symmetry of 



Crystals. By William Barlow ( //V//; /V^^raww) . 205 

 University and Educational Intelligence .... 207 

 Societies and Academies 208 



