72 



NATURE 



{May 17, 1883 



communication was read from Mr. F. Moore, F.Z.S., containing 

 the second part of a monograph of the sections Limnaina and 

 Euplaina, two groups of Diurnal Lepidoptera belonging to the 

 subfamily Euploiin<s. The present paper contained the descrip- 

 tions of many new genera and species belonging to the group 

 Euplaina. — Mr. Alfred Tylor, F.Z. S., read a paper on the 

 colouration of animals, showing that the character of the ornament 

 or decoration differs in the two great divisions of the animal 

 kingdom — the Invertebrata and Vertebrata. Mr. Tylor pointed 

 out that the law of emphasis, well known in architecture, was, 

 in his opinion, applicable to natural history, and showed that 

 the prominent characters of the animal are picked out in colour 

 in precisely the same manner whenever colour is present. He 

 divided his subject into several sections, and exhibited illustra- 

 tions of the more important families in coloured diagrams. — A 

 communication was read from Dr. O. Boettger, of Frankfort- 

 on-the-Main, containing the description of new species of land- 

 shells of the genus Clausilia from the Levant, collected by Vice- 

 Admiral Spratt, F.R.S. — Mr. W. F. Kirby gave an account of 

 a small collection of Hymenopterous and Dipterous insects 

 obtained in the Timor-Laut group of islands by Mr. H. O. 

 Forbes. 



Mathematical Society, May 10. — S. Roberts, F.R.S., vice- 

 president, in the chair. — Prof. M. J. M. Hill, of the Mason 

 College, Birmingham, was elected a member. — Prof. Cayley 

 made a communication on Mr. Wilkinson's rectangular transfor- 

 mation, — Mr. Tucker read abstracts of papers by Prof. Genese, 

 relations between the common points and common tangents of 

 two eonics ; by Mr. W. R. \V. Roberts, on the motion of a 

 particle on the surface of an ellipsoid; and b/ Mr. K. A. 

 Koberis, on unicursal twisted quartics, part ii. ; he also runde a 

 communication on two concentric circles. The circles con- 

 8 dered were a circle which the auhor proposes to call the 

 "Triplicate-Ratio" (T.R.) circle and Brocard's circle. If 

 through a point (P) within a triangle ABC (whose trilinear co- 

 ordinates are 2a A/ k, lb A /k, IcA/k, where k stands for 

 a- + b- + c-), straight lines DPE\ EPF\ FPD l be drawn, 

 then the circle DD 1 E£ 1 FF 1 is the T. K. circle. The origin 

 ol the name is due to the fact that the intercepts 0.1 the sides 

 (DD 1 , £E l , FF 1 ) are equal to a 3 /n, 6 3 /k, c 3 /k respectively 

 If \- — a-b- + b-c- + c-a- and /i = \/x, then the triangles 

 DEF, D l E l F l , which are equal to one another, and are similar 

 to ABC, have their sides = /ia, /id, fiC The lengths D 1 E, 

 E l F, F'D are equal to abcJK, so that the perimeter of the 

 above-named hexagon is (a 3 + b 3 + c 3 + %abc)l k. Other curious 

 properties were pointed out. If the angle B FD be denoted by 

 oi, then cot a = cot A + cot B + cot C, and several other trigono- 

 metrical relations were indicated. If through A, B, C lines are 

 drawn parallel to the sides of DEF, D l E l F 1 , these by their 

 intersections determine five of the points on Brocard's circle, the 

 other two Brocard points being P and H (the centre of the 

 circum-circle). Lastly the trilinear equations to the two circles 

 were given, and it was shown that the two circles are concentric. 

 The T.R. circle also divides each side into segments which are 

 in the duplicate ratios of the sides. — The Rev. M. M. U. 

 Wilkinson read a second paper on spherical functions. 



Geological Society, April 25.— Mr. J. W. Hulke, F.R.S. , 

 president, in the chair. — Rev. William Franklen Evans, Ernest 

 Hall Hedley, and Henry James Plowright were elected Fellows, 

 and Dr. J. S. Newberry, of New York, a Toreign Member of 

 the Society. — The following communications were read : — On 

 the skull of M'galosaurus, by Prof. R. Owen, C.B., F.R.S. 

 The specimens described in this communication were obtained 

 by Edward Cleminsha.v from the freestone of the Inferior Oolite 

 near Sherborne (Dorset) from some blocks which had been 

 quarried for building purposes. These were sent by him to the 

 British Museum, where the remains have been developed. One 

 block includes a great proportion of the right side of the facial 

 part of the skull, the missing parts being the fore-end of the 

 premaxillary, the suborbital end of the maxillary, and the upper 

 hinder pjinted termination of the same bone. Ten teeth are 

 preserved in the maxillary bone. Another block contains the 

 outer side of the right mandibular ramus with teeth and with 

 some other fragments. In a third block is the anterior part of 

 the left mandibular ramus with portions of the teeth. These 

 remains were described in detail ; and in conclusion the author 

 discussed the bearing of these and other Megalosaurian remains 

 upon our knowledge of the structure of that animal and its affinity 

 to existing Reptilia, and criticised some of the evidence on which 



the relationship of the Dinosauria to birds is inferred, a rela- 

 tionship which he had suggested in 1641, but upon grounds 

 which appeared to him to be more satisfactory. — Notes on the 

 Bagshot sands, by Mr. H. W. Monckton, F.G.S. — Additional 

 note on boulders of hornblende picrite near the western coast of 

 Anglesey, by Prof. T. G. Bonney, F.R.S. 



Institution of Civil Engineers, April 8. — Mr. Brunlees, 

 president, in the chair. — The paper read was "On the Diamond 

 Fields and Mines of South Africa." 



Edinburgh 

 Mathematical Society, May 11. — Mr. J. S. Mackay, 

 F.R.S.E., president, in the chair. —Mr. D. Munn, F.R.S.E., 

 gave an address on the geometry of the nine-point circle, and 

 Dr. C. G. Knott, F.R.S.E., a paper on Newton's " Opticks." 



Berlin 

 Physical Society, April 30. — Dr. Pringsheim reported on 

 his recently published measurements of the wave-lengths of the 

 least refractive rays of the solar spectrum. In order to obtain 

 them he used a radiometric torsion apparatus, similar to those 

 used by Crookes, which carried a small mirror by which the 

 revolution of the torsion beam caused by the ray could be 

 observed. The source of liuht were solar rays reflected into a 

 dark room by a heliostat, first united in a focus by a concave 

 mirror, then rendered parallel and directed upon a revolvable 

 grating-mirror, which produced a whole series of spectra. The 

 various divisions of the first spectrum were directed upon the 

 torsion-apparaius by means of a slit, and it was noted up to 

 what wave-length the mirror still performed part of a revolution. 

 In order to exclude the visible rays of the second spectrum which 

 were mixed with the infra-red ones of the first spectrum, and 

 prevent their reaching the torsion-apparatus, Dr. Pringsheim cut 

 them off partly by an iodine solution, partly by an ebonite plate 

 according to Abney. The extreme limit of the spectrum where 

 an effect was still observed was at the wave-length A = o*ooi52mm. 

 — Prof. Neesen reported upon a treatise entitled "On the Con- 

 tractions of Volume as a Measure of Chemical Affinities," sent 

 to the Society for publication in its Transactions by Herr Miiller 

 Erzbach of Bremen. He shows in a number of salts formed by 

 selenic and chromic acids that in chemical combination a stronger 

 contraction of volume corresponds to a greater chemical affinity, 

 and is shown in the heat generated when the combination takes 

 place ; while in those salts which show a smaller contraction, 

 acid and base are bound together by less powerful affinity. 



CONTENTS page 



The Fisheries Exhibition 49 



Science and Art 50 



The Transit Instrument 51 



Letters to the Editor :— 



Fossil Alga:.— Dr. A. G. Nathorst ; J. S. Gardner 52 



The Weather and Sunspots. — Dr. A. Woeikof . . 53 

 Sheet Lightning.— Prof. John Tyndall, F.R.S. ; 



Rev. W. Clement Ley 54 



Hydrogen Whistles. — Prof. John Le Conte ; Francis 



Galton, F.R.S 54 



The PilLr of Light.— R. S. Newall, F.R.S. ... 54 

 Remarkable Lunar Phenomenon observed at Weston- 

 super-Mare, August 21, 1861. — C. Pooley ... 54 

 Curious Habit of a Brazilian Moth. — E. Dukinfield 



Jones 55 



Leaves and their Environment. — J. Brown .... 55 



Foam Balls. — An American Subscriber .... 55 



Anthropology, II. By E. B. Tylor, D.C.L., F.R.S. 55 

 The Arctic Meteorological Station on the Lena 



(With Illustration} 59 



The Aurora Borealis. By Prof. Selim Lemstrb'm . 60 



Notes 63 



Our Astronomical Column : — 



D'Arrest's Comet 65 



The Observatory of Rio Janeiro 65 



The Observatory of Moscow 65 



Kiell on Tycho Brahe's Nova 1572 65 



Electricity Applied to Explosive Purposes. By 



Sir F. A. Abel, F.R.S., Hon.M.Inst.C.E. ... 66 



The Iron and Steel Institute .68 



Scientific Serials 70 



Societies and Academies 71 



