388 



NA TURE 



[January 27, 1910 



ground-mass, and hypersthene is altered at its margin to 

 Wotite and quartz. Finally, granules of blue tourmaline 

 occur in the contact-rocks. In the gneiss, hypersthene is 

 not found, ilmenite is rare, and the rock is foliated. The 

 gneiss is probably a modification of the dacite, but evidence 

 as to its origin is incomplete. It may be the result of 

 extreme contact-metamorphism of a dacite of peculiar 

 character, such as a tuff. Possibly it was produced by 

 differential movement in the dacite before complete con- 

 solidation, and certainly before the intrusion of the grano- 

 diorite. — H. J. Grayson : Recent improvements in rock- 

 section cutting apparatus. The apparatus comprises a 

 slitting disc of mild steel and two bronze grinding laps 

 mounted on a substantial wooden table. The discs and 

 laps are each lo inches in diameter, and revolve at about 

 goo revolutions a minute. The discs and laps are con- 

 nected with endless belts, which in turn are connected 

 with wheels driven by a i-horse-power electric motor. 

 Special clamps are used to attach the rock-specimen and 

 to cut the slice. A goniometric crystal-holder, permitting 

 of slicing in any desired direction, is described, and can 

 be fitted to one of the clamps. Clamps swinging radiallv 

 across the grinding laps permit the parallel grinding of the 

 slice to any thinness. A polishing lap can be placed in the 

 position of one of the grinding laps. The finishing of the 

 slice is done by hand on a slate disc. 



Zoological Society, January i8.— I'rof. T. Rose Bradford, 

 F.R.S., vice-president, in the chair. — S. A. Neave ; 

 Collections of butterflies made during four years spent in 

 northern Rhodesia and adjacent territories. The collection 

 comprised 450 species, of which thirty were new to science, 

 besides several rare and little-known species, including the 

 rare Acraea mirifica. Lathy, and the hitherto unknown 

 female. — J. T. Cunning-ham : Marine fishes and inverte- 

 brates of St. Helena. The scientific results of a visit to 

 the island in February and JMarch, 1909, for the purpose 

 of investigating the condition and prospects of the fisheries 

 of the island. The author's report on the results of the 

 investigation from the economic point of view has been 

 presented to the Colonial Office. The invertebrates 

 collected have been e.xamined and identified by specialists 

 of the Natural History Museum, namely, Dr. Caiman, 

 Mr. Edgar Smith, Prof. Jeffrey Bell, and Mr. Kirk- 

 patrick, the last-named having described a new species of 

 sponge and a new hydroid. The fishes have been worked 

 out by the author himself, and include two new species, 

 one belonging to the Stromateida; and one to the 

 Cyphosidae. The three kinds of Albacore occurring at 

 St. Helena are shown to be identical with the three species 

 diagnosed at Madeira by the Rev. R. T. Lowe in 1839, 

 namely, Thynnus alaloitga, T. albacora, and T. obesus, 

 species which have been confused or rejected by recent 

 ichthyologists ; the synonymy and distribution of these are 

 for the first time correctly elucidated. — Dr. W. T. 

 Caiman ; Second and concluding part of a report on new 

 or rare Crustacea of the order Cumacea, from the collec- 

 tion of the Copenhagen Museum. This portion of the 

 report ^ deals with the families Nannastacidae and 

 Diastylids, and twenty-seven species are described, all of 

 which are regarded as new, and three new genera are 

 established.— Prof. W. M. Smallwood : Hydroids and 

 nudibranchs of Bermuda. 



Institute of Metals, January 19.— Sir Gerard A. Munfz, 

 Bart., president, in the chair. — O. F. Hudson and 

 E. F. Law : A contribution to the study of phosphor- 

 bronze. _ This paper was intended to amplify the 

 conclusions arrived at by A. Philip, who presented a 

 contribution on phosphor-bronze to the Institute of 

 Metals at the Birmingham meeting of the institute in 

 igo8. The authors endeavoured to indicate the rela- 

 tion between the mechanical and other properties of 

 the copper-tin-phosphorus alloys and their constitution 

 and structure. A useful diagram was included in the paper 

 showing the constitution of all the alloys containing up 

 to 25 per cent, of tin. The paper included notes on the 

 examination and analysis of the phosphor-bronzes, and was 

 illustrated by a remarkably clear and numerous collection 

 of photomicrographs illustrating the structure of the 

 alloys. Many of these photographs were originally of 

 NO. 2100, VOL. 82] 



1000 diameters, and these were further enlarged by being 

 projected on a screen from lantern-slides made from auto- 

 chrome plates, the marvellous blue-green and red colourings 

 of the various constituents thereby being brought before 

 the notice of the audience in a very novel and effective 

 manner. — T. Vaughan Hugrhes : The failure in practice of 

 non-ferrous metals and alloys, with particular reference to- 

 brass loco-tubes. This was essentially a practical, as 

 distinct from an academic, paper, and dealt especially 

 with an investigation into the cause of a breakdown of 

 brass loco-tubes which had led to serious casualties and a 

 Government inquiry. The failure was found to be due to 

 the formation of a " scale," only 005 mm. thick, which 

 offered a resistance of 20 megohms to an E.M.F. of 250 

 volts when dry and 150,000 ohms when wet. This elec- 

 trical measurement showed the heat conductivity of the 

 scale, and explained the over-heating of the tube at the 

 point where the breakdown had occurred. — C. O. 

 Bannister : The use of carbonaceous filters in the smelt- 

 ing of zinc. The paper was a corollary of that entitled 

 " Notes on the Production of Pure Spelter," by J. S. G. 

 Primrose, read at the Manchester meeting of the institute 

 in October, 1909. Mr. Bannister described particularly the 

 filters used in the Hopkins fumeless zinc process. The 

 process was stated to have begun with the object of pro- 

 ducing lead-free zinc only, but it now embraced three 

 objects — the manufacture of pure spelter, the prevention 

 or reduction of zinc fume, and the obtaining of higher 

 yields. 



Roval Meteorological Society, January 19. — H. 

 Meilish : Presidential address, on some relations of 

 meteorology with agriculture. The close dependence of 

 agriculture upon climate and upon the periodical varia- 

 tions of the weather has been recognised from the earliest 

 times, but the relations are of such a complicated character, 

 and the difficulty of separating the effects of the different 

 factors is so considerable, that as much progress as might 

 have been expected has perhaps not been made in applying 



. the data of meteorology to the purposes of agriculture. 



I The president first referred to the writings of various 

 authors on the subject of temperature and rainfall, as 

 affecting the wheat and other crops, and then proceeded to 

 deal with such questions as the liability of some crops, and 

 especially of fruit, to injury from frosts ; the influence 

 exercised by forests upon climate, and especially upon 

 rainfall; and the study of phenology. He next considered 

 what steps meteorologists could take to further the appli- 

 cation of the data of their science to the various problems 

 of agriculture. It is doubtful whether farmers make as 

 much use of the forecasts and weather reports as they 

 might. Possibly this may arise because they are not 

 familiar with the technical terms in which the reports are 

 necessarily couched. This might be remedied in the course 

 of time if instruction on the subject could be worked into 

 the courses at the agricultural schools and colleges. The 

 Royal Meteorological Society has lost no opportunity of 

 urging the importance of the subject to farmers, and also 

 the inclusion of meteorology under the head of nature- 

 study in the schools, and there are reasons to think that 

 this is having some effect. 



Manchester. 

 Literary and Philosophical Society, December 14, 

 1909. — Mr. Francis Jones, president, in the chair. — Dr. S. 

 Russ : A note on radio-active recoil. When radium emana- 

 tion is condensed at the bottom of a glass tube from which 

 the air has been removed, active deposit particles are 

 radiated up the tube. This phenomenon has been attributed 

 to the recoil of the atom when an a particle is ejected 

 from it. A disc suspended above the emanation may be 

 the recipient of the active deposit particles. An analysis 

 has been made of the decay curves exhibited by such a 

 disc when exposed for different times. The conclusions 

 arrived at are that the numbers of Radium A and radium 

 B particles projected from the emanation are about equal, 

 and that in comparison with them the quantity of radium 

 C projected is insignificant. This latter result has recently 

 been shown experimentally by Dr. Makower and the 

 author. — D. M. S. Watson : A preliminary account of the 

 bibliography of the post-Triassic Sauropterygia. 



