Dec. 1st, 1887.] 



SCIENTIFIC NEWS. 



235 



pointed out, and stress was laid upon tlie advantages wliicli 

 would in many localities be secured by the application of elec- 

 tricity to the tiring of shots. 



The author devoted much attention to the subject of safety- 

 lamps, and much stress was laid upon the unsafe nature of the 

 Davy, Clanny, and Stephenson lamps, in their original forms, 

 under the present conditions in regard to the air-currents met 

 with in mines. It was pointed out that simple modifications of 

 these, applicable to existing lamps, rendered them comparatively 

 very safe, so that the e.xclusion of the ordinary or '■ unprotected " 

 forms of those lamps by the Act recently passed need not have 

 entailed any serious hardship or inconvenience. 



An account was given of the great progress which had been 

 made, within the last tv\o years, towards providing the miner 

 with a thoroughly portable, self-contained electric-lamp, capable 

 of furnishing a light equal to that of the best safety lamps, 

 during the entire period of a working-shift. The results obtained 

 with secondary-battery lamps devised by Mr. Swan and Mr. 

 Pitkin, and with the primary- battery lamps of Schanschieff, 

 Coad, Blumberg, and others, were described. The cost of these 

 appeared at present the most serious obstacle to the extensive 

 use of electric-lamps by the miner. Electric-light installations, 

 for illuminating the pit bottom, the main haulage roads to some 

 distance, and the screens, sidings, offices, etc., on the suriace, 

 had a'ready been adopted at some extensive collieries with bene- 

 ficial results, and a very important future was opening up for the 

 applications of electric-lighting in connection with coal mines. 



THE GEOLOGICAL SOCIETY. 



AT a meeting held on November 9, Prof. J. VV. Judd, F.R.S., 

 President, in the chair, the following communications 

 were read : — 



1. " Note on the so-called ' Soapstone ' of Fiii." By Henry B. 

 Brady, F.R.S. 



The Suva deposit, which has a composition very similar to 

 that of the volcanic muds at present forming around oceanic 

 islands in the Pacific, is friable and easily disintegrated. The 

 colour ranges from nearly white to dark grey, the mass being 

 usually speckled with minerals of a darker hue. 



The common grey friable rock yields a residue consisting 

 mainly of Foraminilera with a few Ostracoda. Of three 

 specimens examined, I is a light-grey rock from close to the sea- 

 level ; 2, of a lighter colour, from 'about 100 feet elevation; 3 is 

 nearly white and somewhat harder, and was derived from an 

 intermediate point. 



Notes are given on the rarer and more interesting species, 

 together with a list of the 92 species of Foraminifera found. Of 

 these, 87 are forms still living m the neighbourhood of the 

 Pacific islands. Two of the remaining 5 are new to science, and 

 the rest extremely rare. The author concluded that these 

 deposits are of Post-Tertiary age, formed at depths of from 150 

 to 200 fathoms in the neighbourhood of a volcanic region. The 

 following new or little-known species were selected for illustra- 

 tion ; — Ellipsoidina ellipsoides, var. oblonga, Seguenza ; 

 Haplophiaginhim rugosum, D'Orb. ; Ehrcnbcrgina biconiis, 

 nov. ; Sphirroidina ornata, nov. 



2. " On some Results of Pressure and of Intrusive Granite in 

 Stratified Palfeozoic Rocks near IVIorlaix, in Brittany." By Prof. 

 T. G. Bonney. 



The author briefly described the banded Palaeozoic slates in 

 the neighbourhood of Morlaix, and gave a general account of 

 their microscopic structure. They are greatly contorted and 

 folded, and have evidently undergone very severe pressure. 

 The result of this has been the development of minute scales of 

 a light-coloured mica, especially in the darker bands and certain 

 corresponding changes in the more quartzose layers. In certain 

 places these handed slates, after they have attained the afore- 

 said condition, have been affected by intrusive granites. The 

 result has been the intensification of the changes which were 

 already incipient. The quartz granules have been doubled in 

 size, the flakes of mica have become four or five times as large, 

 the black material of the argillaceous bands has been gathered 

 into large granules, and seemingly reduced in quantity (probably 

 by partial oxidation of the carbon), and in some cases andalusite 

 crystals or grains of considerable size have been developed. The 

 rock has become comparatively hard, instead of friable, and the 

 cleavage-planes are " soldered up " by the development of mica 

 along them. 



3. " On the Position of the Obermittweida Conglomerate." By 

 Prof. T. McK. Hughes. 



The author gave an account of a visit to the section at Ober- 

 mittweitla, fifty miles S.W. of Dresden, where there is an 

 apparent intercalation of conglomerate and sandstone in a 

 gneissic series. West of the stream at Obermittweida there is 

 seen a crushed but not much altered conglomerate of felsite and 

 other pebbles, above which gneiss and mica-schist rest, 

 apparently in true sequence numerically. Below the con- 

 glomerate no rocks were seen, but at a little distance to the 

 eastward coarse flaked muscovite-schists and gneissic rocks 

 were exposed, apparently underlying it. By a diagram the author 

 showed how the conglomerate might belong to much newer beds 

 caught in a synclinal fold of the schists, and he advanced various 

 arguments in support of this explanation. 



4. " On the Obermittweida Conglomerate: its Composition and 

 Alteration." By Prof. T. G. Bonney. 



The author was indebted to Professor Hughes for the oppor- 

 tunity of examining a fine series of specimens of this rock, 

 collected by the latter. 



The materials appear to have undergone a certain amount of 

 metamorphism, and the author is of opinion that the materials 

 are rather more altered than is usual in Palaeozoic greywackes 

 and conglomerates, but that the comparatively small amount of 

 alteration, and the character of the included fragments, render it 

 highly improbable that the conglomerate is in stratigraphical 

 sequence with the above-described gneiss, or with any similar 

 series of rocks ; and so, if Archeean, it must belong to one of the 

 latest epochs in that period. 



5. " Notes on a part of the Huronian Series in the neighbour- 

 hood of Sudbury (Canada)." By Prof. T. G. Bonney. 



The specimens noticed by the author were in part collected by 

 him in the summer of 1S85, when the Canada Pacific Railway 

 was in process of construction, and in part subsequently supplied 

 to him by the kindness of Dr. Selwyn, Director-General of the 

 Geological Survey of Canada. 



The eastern edge of the district assigned to the Huronian con- 

 sists of rocks, which may possibly be part of the Laurentian 

 series modified by pressure. But after crossing a belt of these, 

 barely a mile wide, there is no further room for doubt. All the 

 rocks for many miles are distinctly fragmental, and are grits, 

 conglomerates and breccias, which are described as far as about 

 two miles west of Sudbury. The included fragments in these 

 rocks appear to have undergone some alterations subsequent to 

 consolidation ; these are described. In some cases the changes 

 appear to be anterior to the formation of the fragments. The 

 matrix also has undergone some change, chiefly the enlargement 

 of quartz grains, and the development or completion of mica- 

 flakes, as in the Obermittweida rock. 



The author discussed the significance of the changes in these 

 rocks, and states that, in his opinion, the name Huronian, at 

 present, includes either a series of such great thickness that the 

 lower beds are more highly altered than the higher, or else two 

 distinct series ; and he inclines to the latter view. Both, how- 

 ever, must be separated from the Laurentian by a great interval 

 of time, and the newer reminds him of the English Pebidians. 



MIDDLESEX NATURAL HISTORY SOCIETY. 



THE members of this Society held a meeting on the 8th Nov., 

 at the Chandos Rooms, when Dr. Geikie, the Director- 

 General of the Geological Survey, delivered an interesting ad- 

 dress illustrative of the necessity of co-operation among fellow- 

 workers in geology, and dealing with some of the difficulties 

 with which geologists are met in explaining some of the pro- 

 blems presentedtothem. One subject in geology, which bethought 

 v.as interesting above all others, was the history of topograph}-. 

 He knew no department in the science so absolutely fascinating, 

 and he wished more particularly to call attention to some of the 

 results of denudation, or the operation of the various forces of 

 nature upon the surface of the earth. It was a matter of great 

 importance to be able to study this problem in regions where 

 the rocks had not been disturbed at all by the process to 

 glaciation, and in that respect he wished more particularly of 

 deal with the strip of country extending from the west of 

 Cornwall to the north of the Thames. All over the central 

 and northern parts of the British Islands the surface of the 

 ground had been subjected to the action of ice, and the 



