Feb, 15, 1877] 



NATURE 



\M 



SOCIETIES AND ACADEMIES 



London 

 Mathematical Society, February 8. — Mr. C. W. Merri- 

 field, F.R.S., vice-president, in the chair.- — The following com- 

 munications were made to the Society : — On the area of the 

 quadrangle formed by the four points of intersection of two 

 conies, by C. Leudesdorf. — A certain series, by Mr. J. W. L. 



d X d y 



Glaisher, F.R.S. — The differential equation /-^ + ~7~7> = o, 



by Prof. Cayley, F.R.S. — On the classification of loci, and a 

 theorem in residuation, by Prof. Clifford, F.R.S. 



Zoological Society, February 6. — Osbert Salvin, F.R.S., 

 in the chair. — Mr. Sclater exhibited and made remarks on some 

 unnoticed ciiaracters in the original and unique specimen of 

 Comrie's Manucode {Manucodia comrii, P.Z. S., 1876, p. 459). 

 - — Mr. Howard Saunders exhibited a specimen of the Panay 

 Sooty Tern {Sterna anccstheta), which had been obtained on the 

 English Coast, and was the first recorded occurrence of this bird 

 in the British Islands. — Dr. A. Giinther, F.R.S., read a memoir 

 on the tortoises collected by Commander Cookson, R.N., during 

 the visit of H.M.S. Pettrel to the Galapagos Islands. The main 

 results of Commander Cookson's visit consisted in giving us a 

 knowledge of the tortoise of Abingdon Island {Testudo abin^- 

 doni) and of the tortoise of the north of Albemarle Island (7\ 

 vi{crophyes).—h. communication was read from Mr. Robert 

 Collett containing an account of his observations on Phylloscopus 

 borealis, as met with on the coast of the Varanger Fjord and 

 adjacent parts of Finmark. — Mr. Sclater read a note on an appa- 

 rently new species of spur-winged goose of the genus Pkclropterus, 

 proposed to be called P. tii^cr, founded on two examples living 

 in the Society's Gardens, which had been presented to the Society 

 by Lieut. -Gen. A. V. Cunningham. — Prof. A. II. Garrod read 

 a paper on the mechanism of the intervertebral substance and on 

 some effects resulting from ihe erect position of man. — A com- 

 munication was read from Sir Victor Brooke, containing notes on 

 the small rusme deer of the Philippine Islands, and giving the de- 

 scription of a new species proposed to be called Cervus nigricans, 

 of which a female example was recently living in the Society's 

 Gardens. — A paper by Mr. O. Salvin and Mr. Ducane Godnian 

 was read giving the description of twelve new species and a new 

 genus of butterflies from Central America. — Dr. Giinther gave 

 an account of the zoological collection made during the visit of 

 H.M.S. Ptterel to the Galapagos Islands, which had been 

 worked out by himself and his assistants in the Zoological De- 

 partment of the British Museum. — Mr. R. B. Sharpe communi- 

 cated the description of a new species of pheasant of the genus 

 Lohiophasis and of a new species of Pitta from the Lawas River, 

 North-west BorneJ. Mr. Sharpe proposed to call the former 

 L. castaneicaudatus, and the Pitta, Pitta ussheri. 



Geological Society, January 10. — Prof. P. Martin Duncan, 

 F.R.S., president, in the chair. — Frederick Tendron and David 

 Thomas were elected Fellows, and Dr. J. F. Brandt, of St. 

 Petersburg, Dr. C. W. Giimbel, of Munich, and Prof. Jidaard 

 Suess, of Vienna, Foreign Members of the Society.— On gigantic 

 land -tortoises and a small fresh-water species from the ossiferous 

 caverns of Malta, together with a .'ist of the fossil fauna, and a 

 note on Chelonian remains from tlie rock-cavities of Gibraltar, 

 by A. Leith Adams, F.R.S., Professor of Zoology in the Royal 

 College of Science, Dublin. The author described three distinct 

 species of tortoises from the Maltese rock-cavities, one of which 

 was of gigantic proportions, and equalled in size any of the living 

 or extinct land Chelonians from the Indian or Pacific Islands. 

 The characteristic peculiarity in the two larger species is a greater 

 robustness of the long bones as compared with the denizens of 

 the Mascarene and Galapagos Islands, with which he had been 

 enabled to contrast them. The largest, on that account, he had 

 named T. robusta ; it rivalled the gigantic Testudo cphippinm 

 (Giinther) in size, showing affinities to it in a few minor characters. 

 A smaller species, T. Sprattii, and a small Lntrcmys, not dis- 

 tinguishable, as far as the few remains extend, from the recent 

 L. europua, besides many fragments of shields of tortoises of 

 various dimensions, had been obtained. These Chelonians were 

 found in conjunction with the remains of the dwarf elephants 

 and other members of the remarkable fauna, collected by Admiral 

 Spratt and the author in the ossiferous rock-cavities of Zebbug, 

 Mnaidra, Benghisa, &c. The paper contained a list of the 

 animal remains hitherto recorded from the Maltese fissure caverns, 

 including three species of dwarf elepliants, two species of Hippo- 



potamus, two gigantic species of Myoxus, a gigantic swan, and 

 other animal remains ; and further, a Note on some Chelonian 

 remains from the rock-fissures of Gibraltar.— On the Corallian 

 rocks of England," by the Rev. J. F. Blake, F.G.S., andW. II. 

 Hudleston, F.G. S. The object of the paper was to describe 

 the rock masses existing between the Oxford and Kimmeridge 

 clays as exhibited throughout England. They occur in five dis- 

 tinct areas which were treated separately. Where best deve- 

 loped, as in Yorkshire and at Weymouth, the series is much 

 more varied than the usual nomenclature indicates ; in both 

 instances a lower mass of limestone, distinct from that represent- 

 ing the "coral rag" of Central England, is present. In York- 

 shire, especially, this limestone is of great importance, and is 

 separated by a " middle calc. grit" from the upper limestone 

 series. These upper limestones were also shown to be separable 

 into two very distinct divisions, especially by their fauna, viz., 

 the "coralline oolite" and "coral rag," which last term is 

 here applied in a restricted sense only to true coral-bearing or 

 inter-coralline beds. The upper beds, called " supra-coralline," 

 were shown, where present, to be of great interest and impoi'tance 

 — and their fauna was for the first time indicated — and the iron- 

 ores of Abbotsbury and Westbury were proved to belong to this 

 portion of the series. The fauna of the Corallian rocks was 

 shown to be very markedly Oxfordian in the lower portions, and 

 equally Kimmeridgian in the upper, while but a limited portion 

 only could be said to have a fauna of its own. The whole series 

 was deposited in lenticular masses of traceable size. 



Physical Society, February 3. — Prof. G. C. Foster, presi- 

 dent, in the chair. — The following candidate was elected a mem- 

 ber of the Society: — Mr. J. Norman Lockyer, F.R.S. — Prof. 

 Osborne Reynolds exhibited a number of experiments in relation 

 to vortex motion in fluids. They have been gradually developed 

 during the last k\f years, but are still in a very incomplete state, 

 and he hopes that others will join him in the inquiry. Probably 

 one reason why so little progress has been made in the deter- 

 mination of the elementary Jaws of fluid-motion is that mathe- 

 maticians have been without experimental data on which to 

 found their calcula'.ions. The well-known rings formed by puffs 

 of smoke have been studied by many high authorities, but not 

 with a view to their general bearing on this subject. Prof. Rey- 

 nolds first showed smoke rings and their interference by means of 

 the apparatus devised by Prof. Tait, and added that although the 

 theory of smoke rings does not imply that vortex motion is pecu- 

 liar to vapours, their existence in liquids was only pointed out by 

 Mr. H. Deacon at a comparatively recent date. In studying 

 the action of the screw-propeller. Prof. Reynolds noticed the 

 systematic manner in which the form of a disc moved obliquely 

 through water is retained by the track of air which it produces. 

 If a flat disc be supported on a light frame and caused to move 

 rapidly through water the motion ceases on withdrawing the 

 hand suddenly ; but if this be done gradually the motion con- 

 tinues. By passing a coloured liquid down a fine tube to the 

 back of the disc, he found that a vortex ring is always 

 formed, which passes to the rear of the disc, and the same effect 

 is produced by dropping water from a height into water covei^ed 

 with a coloured liquid. In a trough about six feet long and at 

 one end of which was a horizontal tube closed with sheet india- 

 rubber, air rings were formed by introducing air into the tube 

 and then striking the india-rubber externally by means of a flat 

 board, and it was shown that a ring is capable of propelling a 

 vane placed in its course, to the front of which it never advances. 

 If the air be replaced by a coloured liquid the ring travels with 

 considerable velocity and the motion of a solid body of the 

 density of water is in no degree comparable. If a ring travels 

 through a part of a liquid which has previously been coloured, it 

 causes no motion of translation, and Prof. Reynolds concludes 

 that no resistance is offered to their motion. Nevertheless the 

 motion is gradually stopped, but the ring is constantly enlarging 

 by gathermg water as it travels, and its momentum remains 

 nearly constant. After adverting to the methods adopted to 

 ascertain the direction and velocity of motion, the initial form of 

 the rings was shown to be a spheroid. A solid of this form, 

 however, is very slow in its passage through water, and he con- 

 siders this to be due to friction. He has succeeded in imitating 

 the form of the ring by causing a disc, surrounded by pieces of 

 ribbon, to move through water. Finally, Prof. Reynolds re- 

 ferred to Sir William Thomson's researches on the interference 

 of two rings, and showed that the oscillating rings so produced can 

 be formed in liquids or gases by employing an oval in place of a 

 circular aperture. — The Annual General Meeting of the Society 



