May 17, 1888] 



NA TURE 



7i 



Eriboll to Ullapool was described, reference being made to the 

 further subdivision of the "Pipe-rock" and the Ghrudaidh 

 Limestones (Group I. of Durness section). None of the richly 

 fossiliferous zones of Durness is met with along this line, as 

 they occupy higher horizons. An examination of the fossils 

 recently obtained by the Geological Survey from the Durness 

 ines confirms Salter's conclusions that they are distinctly 

 of an American type, the Sutherland quartzites and limestones 

 tteing represented by the Potsdam Sandstones and Calciferous 

 Sand Group of North America. After the deposition of the 

 limestones, the Cambrian and Silurian strata were pierced by 

 igneous rocks, mainly in the form of sheets, producing important 

 alterations in the sedimentary deposits by contact-metamorphism, 

 the quartzites becoming crystalline, and the limestones being 

 converted into marble. When this outburst of volcanic activity 

 had ceased, terrestrial displacements ensued on a stupendous 

 scale. By means of powerful thrusts the Silurian strata were 

 piled on each other, and huge slices of the old Archaean plat- 

 form, with the Cambrian and Silurian strata resting on it, were 

 driven westwards for miles. With the view of illustrating the 

 extraordinary complications produced by these movements, a 

 series of horizontal sections was described, drawn across the line 

 between Eriboll and Ullapool. The evidence relating to regional 

 metamorphism was next referred to, from which it is obvious 

 that with each successive maximum thrust there is a progressive 

 amount of alteration in the displaced masses, as the observer 

 passes eastwards to the higher thrust-planes. Eventually the 

 Archajan gneiss is so deformed that the pre-Cambrian foliation 

 disappears and is replaced by new divisional planes ; the Cam- 

 brian grits and shales are converted into schists ; the Silurian 

 quarti'ites into quartz-schists ; the limestones become crystalline ; 

 the sheets of intrusive felsite, diorite, and granitoid rock pass 

 into sericite schist, hornblende-schist, and augen-gneiss respect- 

 ively. These researches furnish a vast amount of evidence in 

 support of the theory that regional metamorphism is due to the 

 dynamical and chemical effects of mechanical movement acting 

 on crystalline and clastic rocks. It is also c'ear that regional 

 metamorphism need not. be confined to any particular geological 

 period, because in the N.W. Highlands, both in pre Cambrian 

 time and after the deposition of the Durness Limestone (Lower 

 Silurian), crystalline schists and gneiss were produced on a 

 magnificent scale. After the reading of this Report, the Survey 

 was congratulated on its work by the President, Prof. Lapworth, 

 Prof. Judd, and other speakers. — On the horizontal movements 

 of rocks, and the relation of these movements to the formation 

 of dykes and faults, and to denudation and the thickening of 

 trata, by Mr. William Barlow. — Notes on a recent discovery of 

 Stigmaria ficoides at Clayton, Yorkshire, by Mr. Samuel A. 

 Adamson. 



Zoological Society, April 30. — Fifty-ninth Anniversary 

 Meeting.— Prof. Flower, F.R.S., President, in the chair. — After 

 he Auditors' Report had been read, and some other preliminary 

 ess had been transacted, the Report of the Council on the 

 edings of the Society during the year 1887 was read by Mr. 

 Sclater, F. R.S., the Secretary of the Society. It stated that 

 he number of Fellows on January 1, 1888, was 3104, showing 

 1 decrease of 42 as compared with the corresponding period in 

 1887. A large number of valuable communications received at 

 he usual scientific meetings held during the session of 1887 had 

 cen published in the annual volume of Proceedings, which 

 d 730 pages, illustrated by 55 plates. Besides this, one 

 >art of the twelfth volume, viz. Part C, of the Society's quarto 

 I ransactions, illustrated by seven plates, had been issued, and 

 event] other parts, of Transactions were in a forward state. 

 I he volume of the Zoological Record for i£86 had been sent 

 Ht in the month of January of this year to about 140 sub- 

 cnbers. The new edition of the Library Catalogue, spoken of 

 n the last Annual Report as ready for issue had been published 

 ast summer. Two important additions had been made to the 

 mrldings in the Society's Gardens during the past year. The 

 irsf of these, the wolves' and foxes' dens, which were commenced 

 n 1886, had been erected by the Society's staff, under the super- 

 ision of Mr. Trollope, by whom the plans were drawn, and 

 completed in November last. The second addition was a new 

 viary for flying birds which had been erected on the water- 

 pwUr lawn, opposite the eastern aviary. This aviary is 105 feet 

 bop 62 feet broad, and 27 feet high in the centre of the roof, 

 Inch is formed of galvanized wire. The visitors to the Society's 

 aniens during the year 1887 had been "altogether 562,898; 

 he corresponding number in 1886 was 639,674. Mr. F. E. 



Beddard, Prosector to the Society, had been appointed 

 Davis Lecturer for the present year, and had commenced a 

 course often lectures on " Reptiles, living and extinct." These 

 lectures were a continuation of a series given last year in con- 

 nection with the London Society for the Extension of University 

 Teaching. The number of animals in the Society's collection 

 on the 31st of December last was 2525, of which 735 were 

 mammals, 1331 birds, and 459 reptiles. Amongst the additions 

 made during the past year, 13 were specially commented upon as 

 of remarkable interest, and in most cases representing species 

 new to the Society's collection. About 29 species of mammals 

 21 of birds, and 3 of reptiles, had bred in the Society's Gardens 

 during the summer of 1887. The Report concluded with a long 

 list of the donors and their various donations to the Menagerie 

 during the past year. — A vote of thanks to the Council for their 

 Report was then moved by Dr. David Sharp, seconded by Mr. 

 Robert McLachlan, and carried unanimously. — The Report 

 having been adopted, the meeting proceeded to elect the new 

 Members of Council and the Officers for the ensuing year. The 

 usual ballot having been taken, it was announced that Dr. John 

 Anderson, F.R.S., F. Du Cane^ Godman, F.R.S., John W. 

 Hulke, F.R.S., Osbert Salvin, F.R.S., and Lord Walsingham, 

 F.R.S., had been elected into the Council in place of the retiring 

 members, and that Prof. Flower, C.B., F.R.S., had been re- 

 elected President, Mr. Charles Drummond, Treasurer, and Dr. 

 Philip Lutley Sclater, F.R.S., Secretary to the Society, for the 

 ensuing year. — The meeting terminated with the usual vote 

 of thanks to the Chairman, proposed by Lord Arthur Russell, 

 seconded by Prof. G. B. Howes, and carried unanimously. 



Minera'.ogical Society, May 8.— Prof. Bonney, F.R.S., 

 Treasurer, in the chair. — The following papers were read : — 

 Notes on some minerals from the Lizard, by Mr. J. J. H. Teall. 

 — Contributions to the study of pyrargyrite and proustite, with 

 analyses by Mr. G. T. Prior, by Mr. H. A. Miers. — On Ccrnish 

 dufrenite, by Prof. E. Kinch. — On a peculiar variety of horn- 

 blende from Mynydd Mawr, Carnarvonshire ; on a picrite from 

 the Clicker Tor District, by Prof. T. G. Bonney, F.R.S. 



Paris. 



Academy of Sciences, May 7. — M. Janssen, President, in 

 the chair. — Note on the introduction of the element of mean 

 averages in the interpretation of the results of statistical returns, 

 by M. J. Bertrand. A demonstration is offered of the following 

 theorem : Whatever be the number of urns (ballot-boxes and 

 the like) and their composition, the law of discrepancies is the 

 same for a single urn of given composition ; but this urn will not 

 yield the desired mean average. Hence in order to compare 

 the results of statistical returns with those of abstract calculation 

 two different urns must be assumed, the mean results being 

 assimilated to the drawings made from the first, and the dis- 

 crepancies to the results yielded by the second. — New theory of 

 the equatorial coudt (continued), by MM. Lcewy and Puiseux. 

 In this paper an explanation is given of the special processes 

 applicable to the equatorial region, and of the physical methods 

 employed to estimate the flexion of the axes. In a final paper 

 the results will be given which have already been obtained in 

 the application of this theory to the equatorial coude of the Paris 

 Observatory. — On the convergence of a continuous algebraic 

 fraction, by M. Halphen. Three years ago the author com- 

 municated to the Academy the results of his researches concern- 

 ing continuous fractions, which serve to develop the square ror t 

 of a polynome of the third degree. In the present paper he 

 extends his investigations to the case of a continuous fraction 



obtained by developing the function f(x) = - — )J2_Z ±l t 



y — x 

 where F indicates a polyncme of the fourth or of the third 

 degree. — On M. Massieu's characteristic functions in thermo- 

 dynamics, by M. H. Le Chatelier. It is shown that these 

 functions may be presented under a form somewhat different 

 from that which they are usually made to assume, but which is 

 more convenient for practical purposes. — On the variation of the 

 specific heat of quartz with the temperature, by M. Pionchon. 

 From the experiments the results of which are here tabulated 

 it appears that from about 400° to 1200 C. the specific heat of 

 quartz is constant and equal to 0*305. Thus the increase in the 

 specific heat of this mineral is entirely confined to the interval 

 between o° and 400° C, a result which presents several points 

 of interest in connection with M. Joubert's researches on the opti- 

 cal properties of the same substance. — On the theory of diamag- 



