4o6 



NA TURK 



[February 26, 1903 



Geological Society, February 4. — Prof. Charles Lap- 

 worth, F.R.S., president, in the chair. — The granite and 

 greisen of Cligga Head (West Cornwall), by Mr. J. B. 

 Scrivenor. The small granite-mass between St. Agnes 

 and Perranporth is a remnant of a larger mass which 

 has been partly denuded and partly hidden by a lault ; 

 " bedding " is well developed. The granite bordering the 

 bedding-planes has been altered into greisen. Each greisen- 

 band contains a quartz-vein, marking the original fissure 

 along which metasomatism took place ; the veins contain 

 tourmaline, cassiterite, wolfram, mispickel and chalco- 

 pyrite. Two main reactions appear to have taken place in 

 the formation of the greisen : the felspars affording topaz, 

 muscovite and secondary quartz ; the biotite brown tourma- 

 line, magnetite and secondary quartz. The greisen is an 

 example of Prof. Vogt's " pneumatolytic " action in 

 thoroughly acid rocks. — Notes on the geology of Patagonia, 

 by Mr. J. B. Scrivenor. The sedimentary strata consist of 

 Tertiary, Cretaceous and Jurassic formations, which, with the 

 exception of the Jurassic, yield varied faunas, both vertebrate 

 and invertebrate. Except in the north, where intrusions of 

 an acid type have disturbed the sediments, the southerly dip 

 is so gentle as only to be appreciable where sections can be 

 followed for some distance. Mr. Hatcher considers that 

 an unconformity separates the Magellanian and Guaranitic 

 Series, also the Cretaceous and Jurassic. Very little is 

 known of the igneous rocks. Apart from those of the 

 Cordillera, there are vast plateaux of basalt and intrusions 

 of quartz-porphyry. The specimens of igneous rocks col- 

 lected from the moraines of the Cordillera comprise biotite- 

 granite, hornblende-granite, quartz-mica-diorite, gabbro, 

 hornblende-picrite, quartz-porphyry, rhyolite, obsidian, ophi- 

 tic olivine-dolerites, olivine-basalts and acid tuffs. The basalt- 

 flows cover an enormous area. They slope gently towards 

 the Atlantic, and are cut off from the Cordillera by a longi- 

 tudinal depression. All that can be said of their age is that 

 they are older than the transverse depressions of the Cor- 

 dillera, and older than the glaciation of the eastern slopes 

 of that chain. The Tehuelche Pebble-Bed, which covers 

 nearly the whole of Patagonia, has been ascribed to marine 

 action by some authors, by others to glacial action. A 

 third suggestion is the agency of big rivers. The drainage- 

 system includes several eastward-flowing rivers and 

 numerous lakes, some of which occupy transverse valleys 

 cutting through the Cordillera. — On a fossiliferous band at 

 the top of the Lower Greensand, near Leighton Buzzard 

 (Bedfordshire), by Mr. G. W. Lamplugh and Mr. J. F. 

 Walker. This paper describes a newly-discovered fossil- 

 iferous band at the top of the Lower Greensand, overlain 

 by the Gault, in the sand-pits at Shenley Hill, near Leighton 

 Buzzard, in Bedfordshire. The fossils of this band present 

 a different facies from that of any other previously-known 

 fossiliferous horizon of the Lower Greensand, and show 

 closer affinities with the fauna of the Upper Greensand than 

 have hitherto been recognised in any deposit below the 

 Gault. The fossiliferous bed is marked off from the under- 

 lying unfossiliferous " silver-sands," but more from the 

 overlying Gault. Stratigraphically it forms part of the 

 Lower Greensand, and cannot be considered to belong to 

 the Gault. The fossils constitute the newest Lower Cre- 

 taceous fauna as yet recognised in England. 



Royal Meteorological Society, February iS. — Captain 1). 

 Wilson-Barker, president, in the chair. — Mr. E. Mawloy 

 presented his report on the phenological observations for 

 1902. In all parts of the British Isles, the phenological 

 year ending November 30, 1902, was for the most part cold 

 and sunless. Rain fell at unusually frequent intervals, so 

 that, although the total quantity proved deficient, there at 

 no time occurred any period of drought. Wild plants were 

 everywhere behind their mean dates in coming into flower, 

 but the departures from the average were, as a rule, slight, 

 until about the middle of May. After that time, until the 

 end of the flowering season, the dates of blossoming were 

 later than in any other year since the present series of re- 

 cords was instituted in 1891. The swallow, cuckoo and 

 nightingale were a few days earlier than usual in making 

 their appearance. The most remarkable feature as regards 

 the weather and its effect on vegetation was the way in 

 which it favoured the growth of all the farm crops, except 

 potatoes and hops. For it is seldom in the same year that 



NO. I739, VOL. 67] 



the yields of wheat, barley, oats, beans, peas, turnips, man- 

 golds and grass are alike abundant, even in a single dis- 

 trict, much less in all parts of the kingdom, as was the case 

 in 1902. On the other hand all the fruit crops were more or 

 less deficient, with the exception of strawberries, which 

 yielded well, but were like most other fruits, lacking in 

 flavour. 



Cambridge. 



Philosophical Society, January 19. — Mr. Seward, vice- 

 president, in the chair. — On the invariant factors of a deter- 

 minant, by the president (Dr. Baker). — On the variation 

 with wave-length of the double refraction in strained glass 

 (second paper), by Mr. L. N. G. Filon. — On the alimentary 

 canal of the mosquito, by Mr. A. E. Shipley. The paper dealt 

 with the alimentary canal of Anopheles maculipennis, Meig., 

 special attention being paid to the mechanism by which 

 " biting " is effected and by which the food is pumped up 

 into the pharynx. Three food reservoirs were described. 

 The alimentary canal, the salivary glands and the Mal- 

 pighian tubules were described in detail. — A second memoir 

 on integral functions, by Mr. E. W. Barnes. In this 

 paper the author continues certain researches on the asym- 

 ptotic expansions of integral functions which were published 

 in the Philosophical Transactions of the Royal Society, 

 Series A, vol. excix. pp. 411--500 (1902). Asymptotic ex- 

 pansions are obtained for the standard functions of double 

 sequence, and an attempt is made to classify Taylor's series 

 by means of the asymptotic expansion of the inverse of the 

 mth root of the mth coefficient. — On the theory of shadows, 

 by Mr. H. M. Macdonald. 



Dublin. 



Royal Dublin Society, January 20. — Prof. W. F. Barrett, 

 F.R.S., in the chair. — Prof. J. Joly, F.R.S., gave a further 

 account of his preliminary experiments on the conservation 

 of mass which he had presented at the meeting of December 

 16, 1902. — A paper was read by Dr. W. E. Adeney on the 

 ultra-violet spark spectrum of ruthenium. The first in- 

 stalment of wave-length determinations in spark spectra 

 from the large Rowland spectrometer in the Royal Uni- 

 versity, Dublin, is given in this communication, repro- 

 ductions of photographs from which have already been 

 published in the Scientific Transactions of the Royal Dublin 

 Society, vol. vii., 1901. 1461 lines have been measured 

 between the two extreme limits of wave-lengths 2263 and 

 4560. Kayser has given 1613 lines as occurring in the arc 

 spectrum between the same limits of wave-length. About 

 800 lines are common to both forms of the spectrum. Very 

 few in either list are due to impurities. Exner and 

 Haschek have measured 2250 lines between the same limits 

 ill wave-length ; some 1330 of these occur in the author's 

 photographs. 



Manchester. 



Literary and Philosophical Society, January 20 — Mr. 

 Charles Bailey, president, in the chair. — Mr. Thomas 

 Thorp gave an account of some researches he had made on 

 the production of metallic surfaces having the properties of 

 Japanese " magic " mirrors. A passage was read from 

 " Light, Visible and Invisible," by Prof. Silvanus Thomp- 

 son, pp. 51--52, relative to the manufacture of these mirrors 

 in Japan, from which it appears that scraping is resorted to 

 previous to polishing, great pressure being used. These re- 

 searches were undertaken by Mr. Thorp with a view to 

 determine whether the same " magic " effect can be pro- 

 duced by the ordinary methods of grinding and polishing. 

 Replicas of a Japanese mirror capable of showing the 

 " magic " effect in a very slight degree were made in hard 

 bronze (bell metal). One of these was ground and 

 polished by the method used for glass, &c, considerable 

 pressure being used in the polishing. The result was a 

 decided improvement on the original. The second replica 

 was now ground and polished in a similar manner, but 

 under conditions which prevented flexure during the pro- 

 cesses. The result was a plane mirror, without the 

 " magic " properties. As straining the first mirror had 

 been noticed to give enhanced effects, the plane mirror was 

 now subjected to uniform pressure from the back, when the 

 design was seen to start out in a very decided manner, being 

 much brighter than the rest of the surface. On the mirror 



