Dec. I, 1887] 



NA TURE 



119 



to the death-roll since last June meeting, specially deploring the 

 loss of Prof. Julius von Haast, N.Z., Dr. Spencer Baird, U.S., 

 and Prof. Caspary, of Konigsberg. — Mr. H. N. Ridley gave an 

 account of his natural history collection in Fernando Noronha. 

 The group of islands in question is in the South Atlantic, 194 

 miles east of Cape San Roque. The largest is about five miles 

 long and two miles across at broadest part. Although chiefly 

 basaltic, phonolite rocks crop up here and there. The indigenous 

 fauna and flora seem to have beea much modified, and in some 

 cases extirpated, by human agency. Of mammals, the cat is 

 reported to have become feral, and rats and mice swarm ; Cetacea 

 occasionally frequent the coast. The land-birds comprise a dove, 

 a tyrant, and a greenlet ( Virio). Sea-birds are numerous, though 

 apparently less sj than in the time of the early voyagers. 

 Among reptiles occurs an Amphisba:na, a Skink, and a Gecko ; 

 turtles also haunt the bays. The absence of batrachians and 

 fresh-water fish is noteworthy. A well-known Brazilian species 

 of butterfly is plentiful. Though insects generally are abundant, 

 there are, notwithstanding, but few species. Two shells 

 {Trochus) show a southern distribution, though other marine 

 forms indicate West Indian relationship. Several interesting 

 plants were got, a Solatium with medicinal properties, a new 

 Erythrium, and flower of the "Burra," a Euphorbiaceous 

 tree. Of ferns, mosses and hepatics, lichens and fungi, several 

 interesting sorts were collected. — Mr. Geo. Murray exhibited 

 Vallotiia ovalis from Bermuda and Grenada ; the former sort 

 consisting of a balloon-shaped cell an inch long and two wide. 

 He explained by diagrams the development of V. uti-icularis, 

 incidentally comparing this with Sciadium. — Prof. Marshall 

 Ward showed specimens and made remarks on the peculiar de- 

 velopment of Agaricus (Amillaria) melktts. — Mr. E. A. Heath 

 exhibited examples of fruits of two species of Solarium from 

 Barbados. — A paper was read on the scars occurring on 

 the stem of Dammara rohmta, by Mr. S. G. Shattock. He 

 says that the process of disarticulation of the branches is like 

 that by which a leaf or other organ is shed. The parenchy- 

 matous cells across the whole zone of articulation multiply by 

 transverse division, a layer of cork resulting from the formation 

 of this secondary meristem, and through the distal limits of this, 

 solution of continuity occurs. After this the slender connecting 

 bond of wood is broken across by the weight of the branch or 

 the first trivial violence ; this completion of the process being 

 aided, perhaps, by the tension made upon the wood in conse- 

 quence of the cell-division of the surrounding parenchyma which 

 occurs across its axis. It thus happens that the whole of the 

 parenchymatous system of the stem is closed by cork before the 

 branch is actually shed. — A communication followed, by Messrs. 

 J. G. Baker and C. B. Clarke, on the Ferns of Northern India ; 

 it being a supplement to a memoir published in the Society's 

 Transactions. 



Physical Society, November 12. — Prof. W. E. Ayrton, 

 F.R.S., Vice President, in the chair. — Lieut. Bacon, R.N., was 

 elected a member of the Society. — Owing to the illness of Dr. 

 Shettle, the paper announced to be read by him was postponed. 

 — The following communication was read : —On a geometrical 

 method of determining the conditions of maximum efficiency in 

 the transmission of power by alternating currents, by Mr. T. H. 

 Blakesley. In this paper the author confines himself to the con- 

 sideration of a simple circuit containing generating, conveying, 

 and recipient parts, in which the E M. F. follows the law of 

 sines. The maximum E. M.F.'s of both machines are supposed 

 known, together with the resistance and coefficient of self- 

 induction of the complete circuit. The variable on which the 

 efficiency of transmission depends is the difference of phase of 

 generator and receiver. A geometrical construction is given by 

 which the phase which gives maximum efficiency can be deter- 

 mined. Mr. Kapp thought the construction would not apply 

 where the receiver does mechanical work, owing to the E.M.F. 

 not being a true sine function of the time. He also mentioned 

 an experiment performed on a motor driven successively by 

 alternating and direct currents, in which the apparent power 

 ( V^?' V'?' ) supplied by alternating currents was about five 

 times that required when direct currents were used, the motor 

 giving out the same power in the two cases. From this he 

 inferred that the ratio of power to weight is much greater for a 

 direct than for an alternating current motor. This he considered 

 a serious drawback to the use of alternate currents for trans- 

 mitting power. After some remarks by Prof. Ayrton and Prof. 

 S. P. Thompson, Mr. Blakesley said that by placing a condenser 



between the terminals of the recipient machine a greater currei t 

 could be passed through the receiver than that in the generator 

 and line. — Prof. A. W. RUcker exhibited and described a lecture 

 experiment for determining the velocity of sound. The principle 

 of the arrangement is that used by Fizeau in determining the 

 velocity of light. A vibrating reed is used as the source of 

 sound and a sensitive flame as receiver. A long U-shaped tube 

 has its two ends placed near and parallel to the plane of a per- 

 forated disk, which is capable of rotating about an axis perpen- 

 dicular to its own plane. The reed and sensitive flame occupy 

 similar positions on the opposite side of the disk. On rotating 

 the disk, the sensitive flame flares or is quiescent according as 

 the time taken to travel the length of the tube is an even or an 



T 

 odd multiple of — , where T is the time of one revolution and 



2« 



n the number of holes in the disk. — Mr. Bosanquet exhibited a 

 form of polariscope he had made some time ago for researches 

 on the polarization of the sky. Its chief feature is a compound 

 prism of right- and left-handed quartz'which shows coloured 

 bands with polarized light, whatever be the direction of the 

 plane of polarization. It also forms a very sensitive object for 

 polarimeters. 



Zoological Society, November 15. — Prof. W. H. Flower, 

 F. R.S., President, in the chair, — The Secretary read a 

 report on the additions that had been made to the Society's 

 Menagerie during the months of June, July, August, September, 

 and October, 1887, ^"cf called attention to certain interesting 

 accessions which had been received during that period. — A 

 communication was read from Herr W. von Nathusius, of 

 Konigsborn, on Symbioles equi, a parasite of the horse, causing 

 what is called "greesy-foot," of which he sent specimens for exhi- 

 bition. — The Secretary read a letter addressed to him by Dr, 

 Emin Pacha, dated Wadelai, April 15, 1887, referring to some 

 communications which he was proposing to offer to the Society. 

 — A letter was read from Surgeon-General George Bidie, referring 

 to a case of the breeding of the Elephant in captivity. — Prof. Bell 

 made some obseivations on the "British Marine Area," is 

 proposed to be defined by the Committee of the British Associa- 

 tion. Prof. Bell oppo?ed the idea of omitting the Channel 

 Islands from the British area. — Prof. A. Newton, F.R.S., ex- 

 hibited (on behalf of Mr. W. Eagle Clarke) a specimen of 

 Bulwer's Petrel {Buhveria coluvibina), believed to have been picked 

 up dead in Yorkshire. — Mr. H. E. Dresser exhibited (on behalf 

 of Lord Lilford) specimens of a new species of Titmouse allied to 

 the Marsh-Tit [Parus ater), obtained by Dr. Guillemard in 

 Cyprus, which he proposed to designate Parus Cypriotes. — Mr. 

 Boulenger exhibited a living specimen of a rare African Batrachian 

 {Xenopiis Imvis), which had been sent to him by Mr. Leslie, of 

 Port Elizabeth. — Prof. Flower exhibited a photograph of a speci- 

 men ofRudolphi's \^ha\&{Bala:noptra borealis), taken in October 

 last, in the Thames near Tilbury.— Mr. G. A. Boulenger, read 

 on account of the Reptiles and Batrachians collected by Mr. H. 

 H. Johnston on the Rio del Rey, West Africa. Amongst these 

 were examples of two species of Batrachians new to science. 

 — Mr. Edgar A. Smith read some notes on three species of shells 

 obtained by Mr. H. H. Johnston at the Rio del Rey, Cameroons. 

 — Mr. A. G. Buller read a paper containing an account of tw» 

 small collections of African Lepidoptera obtained by Mr. H. H. 

 Johnston at the Cameroons and the Rio del Rey. — A 

 communication was read from Mr. G. E. Dobson, F. R. S., on 

 the genus Myosorex. The paper contained the description of a 

 new species from the Rio del Rey (Cameroons) district, which 

 he proposed to call Myosorex johustoni, after Mr. H. H. 

 Johnston, who had sent home the specimens.— Mr. G. A. 

 Boulenger gave the description of a new species of Hyla from 

 Port Hamilton, Corea, living in the Society's Gardens, which 

 he proposed to name Hyla stepheni, after its discoverer. 



Institution of Civil Engineers, November 8. — Mr. G. 

 B. Bruce, the new President, after presenting the medals and 

 premiums announced at the annual meeting in May last, delivered 

 his address on assuming the chair for the first time. Having 

 entered upon his apprenticeship in the locomotive works of 

 Robert Stephenson within a few months of the beginning of the 

 present reign, the President chose the state of engineermg then 

 and in the Queen's Jubilee year as the subject of his remarks. 

 Starting with the workshop, in 1837 machine-tools were practic- 

 ally unknown, reliance being placed upon the skill of the work- 

 men, who could chip and file by hand almost as truly as the 

 machine. It was scarcely credible, but it was a fact, that there 



