December 7, 1905] 



NA TURE 



141 



it can be shown that such a course is suitable to the 

 circumstances of the locality in which the school is placed, 

 yet it is not the intention of the Board to sanction the 

 adoption of this special course in any fresh school." This 

 decision is a little difficult to understand. If it can be 

 shown at present that some schools, in which science takes 

 a specially prominent part, are suitable to the locality in 

 which the school is placed, it would appear reasonable 

 to suppose that other localities in the future may demon- 

 strate the need for a precisely similar type of school, and 

 vet the Board has decided beforehand that — such demon- 

 stration notwithstanding — there shall be no more such 

 schools. Experience has shown that the so-called " school 

 of science " is capable of supplying just the training boys 

 from elementary schools in manufacturing centres require 

 to prepare them for their work in life, and it is to be hoped 

 in these cases that every encouragement will be given to 

 a definite course of study in science in the schools. All 

 educationists of experience agree with the Board's 

 opinion, expressed in subsequent paragraphs of the report, 

 that premature specialisation in the work of ordinary 

 secondary schools is to be discouraged, and that a well 

 balanced curriculum, comprising literary and practical sub- 

 jects taught in a scientific manner, is of prime importance ; 

 but such agreement does not preclude the possibility of 

 applying special remedies to special needs. It is satis- 



1 ro find that the report contains abundant evidence 



of a continued improvement in the work of secondary 

 schools and technical institutions. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, November 16. — "The Transit of Ions in 

 the Electric Arc." By A. A. Campbell Swinton. Com- 

 municated by the Hon. C. A. Parsons, C.B., F.R.S. 



The paper describes an experiment designed to show that 

 in the electric arc the positive and negative electrodes emit 

 carriers or ions which are respectively positively and 

 negatively charged, and, after travelling across the arc, 

 bombard the opposite electrode. The method adopted re- 

 sembles that employed by Perrin to prove the negative 

 charge carried by kathode rays. A small hole was pierced 

 axialiy through one of the carbon electrodes, and immedi- 

 ately behind this aperture was fixed an insulated Faraday 

 cylinder of brass which had its aperture in line with, and 

 facing the aperture in, the electrode. A galvanometer con- 

 necting the insulated cylinder and the pierced electrode 

 measured any difference of potential between the two. The 

 second electrode was an ordinary carbon pencil, and as 

 this was made positive or negative it was found that positive 

 or negative charges respectively were communicated to 

 the insulated Faraday cylinder, provided the arc covered 

 the aperture in the pierced electrode, but not otherwise. 

 These results, which confirm the theory as enunciated 

 H ere obtained both in air at atmospheric pressure 

 and also in vacuo up to what could be obtained with a 

 mechanical air pump. The galvanometer deflections in- 

 creased considerably with the degree of exhaustion, and 

 at any given degree a much larger deflection was obtained 

 when the second electrode was made negative and the 

 cylinder was being charged negatively than when the 

 contrary was the case, this corresponding with the known 

 fact that negative ions have a higher velocity than have 

 positive ions. 



Geological Society, November 8. — Dr. J. E. Marr, 

 F.R.S., president, in the chair. — The coast-ledges in 

 the south-west of the Cape Colony : Prof. E. H. L. 

 Schwari. The author compares the shelves of Cape 

 Colony with those described on the European and American 

 sides of the North Atlantic, and he places the " absolute 

 base-level of erosion " at 12,000 feet in North America, 

 8000 feet in Europe, and 1200 feet in South Africa. With 

 these varying heights he correlates the topography of the 

 bordering continents — the sharp divides, open river-valleys, 

 permanent rivers and deltas, of Europe and America, where 

 the movement has been downward and has almost reached 

 bottom, in contrast with the flat undenuded divides, the 

 steep, narrow gorges, the waterfalls, and the rocky river- 

 gates, of South Africa, which is on the upgrade and prob- 



NO. 1884, VOL. 73] 



ably near the top. — The Glacial period in Aberdeenshire 

 and the southern border of the Moray Firth : T. F. 

 Jamieson. One of the most interesting features in the 

 glacial geology of Aberdeenshire is the Red Clay found 

 along the eastern coast of the county. The purer masses 

 of clay seem to have formed in a sheet of water lying in 

 front of the ice, between it and the land, during the retreat 

 of the Aberdeenshire ice, and at a time when the coast 

 was submerged beneath water to a level exceeding 300 feet 

 above the present coast-line. Evidence of the northward 

 motion of the ice is given from stria;, the transport and 

 removal of flints, and the bending-over of the edges of folia 

 of gneiss. The Red Clay is underlain by a Grey Clay, and 

 sometimes covered by a similar one. The author has 

 recently discovered remains of a still older, 'dark indigo 

 in colour, and containing small fragments of sea-shells. 

 On the southern border of the Moray Firth the author 

 gives examples of glacial marking on the rocks, and refers 

 to the transport of boulders, including a huge mass of 

 Oolitic rocks 40 feet thick, a mass of clay once considered 

 to be an outlier of Lias, " pipe-rock," and the fossiliferous 

 Greensand debris at Moreseat, now considered to have been 

 transported by ice. 



November 22. — Dr. J. E. Marr, F.R.S., president, in 

 the chair. — On a new specimen of the chinueroid fish 

 Myriacanthus paradoxus, Ag., from the Lower Lias of 

 Lyme Regis (Dorset) : Dr. A. S. Woodward. The 

 author, having proved that the dorsal fin-spine of the so- 

 called Ischyodus othorhinus is identical with an ichthy- 

 odorulite which has been named Myriacanthus granulatus, 

 inferred that the larger ichthyodorulite M. paradoxus 

 belonged to the same fish as the larger dentition named 

 Prognathodus Guentheri by Egerton. This question has 

 been settled by the discovery by Mr. S. Curtis, in the 

 Lower Lias of Black Ven, of a dorsal fin-spine in direct 

 connection with a mass of decayed cartilage, dermal plates, 

 and teeth. The new fossil warrants the conclusion that 

 Myriacanthus is a chimasroid, closely similar to the Upper 

 Jurassic Chimaeropsis, with (1) a median chisel-shaped 

 tooth in front of the lower jaw; (2) a few tuberculated 

 dermal plates on the head ; and (3) a tuberculated dorsal 

 fin-spine. In these respects it differs from all other known 

 chimaeroids — even from the comparatively primitive types 

 which have been discovered during recent years in the 

 Japanese seas. The Myriacanthidae, in fact, have still no 

 nearer ally than Callorhynchus, with which Egerton 

 originally compared his so-called Ischyodus ortkorhinus. — 

 The rocks of the cataracts of the River Madeira and the 

 adjoining portions of the Beni and Mamor£ : Dr. J. W. 

 Evans. The crystalline rocks of the cataracts of the River 

 Madeira and the lower waters of its tributaries are part 

 of a ridge with a north-westerly and south-easterly strike, 

 similar to that of the Andes in the same latitudes. This 

 strike is especially prevalent in equatorial regions. With 

 the exception of comparatively recent alluvial deposits and 

 a few pebbles of chert, pronounced by Dr. G. J. Hinde to 

 be of marine origin, but uncertain date, only crystalline 

 rocks are met with in the falls. They all appear to be 

 igneous, and are mostly massive in character, though some 

 dyke-rocks occur. In places they are typical gneisses, and 

 thev are often banded, but in some cases they show no 

 signs of foliation. The prevailing type is acid, with a con- 

 siderable proportion of alkalies, especially soda ; but some 

 of the rocks are distinctly basic in character. — The 

 Doncaster earthquake of April 23, iqoj : Dr. Charles 

 Davison. The Doncaster earthquake of 1905 was a twin, 

 with its principal epicentre half a mile north of Bawtry, 

 and the other about 4 miles east of Crowle and close to 

 the centre of the disturbed area of the Hessle earthquake 

 of April 13, 1902. The distance between the two epicentres 

 is about 17 miles. The disturbed area contains about 

 17,000 square miles, including the whole of the counties of 

 Lincoln, Nottingham, Derby, Stafford, Leicester, and Rut- 

 land, the greater part of Yorkshire, and portions of 

 Lancashire, Cheshire, Shropshire, Worcestershire, Warwick- 

 shire, Northamptonshire, Cambridgeshire, and Norfolk. 

 The originating fault runs from about E. 38 N. to 

 YV. 3S S., and appears to be nearly vertical within the 

 south-western focus and inclined to the south-east in the 

 north-eastern focus. The first and stronger movement took 

 place within the south-western focus. A twin-earthquake 



