340 



NATURE 



\Feb. 25, 1875 



vided lie keeps the piece of wood bclween his teeth. If we can 

 now adjust another piece of wood so that it shall always have a 

 determinate position with respect to the eyeball, we may study 

 the motion of the one piece of wood with respect to the other as 

 the eye moves about. For this purpose a small mirror is fixed 

 to a board, and a dot is marked on the mirror. If the eye, 

 looking straight at the image of its own pupil in the mirror, sees 

 the dot in tlie centre of the pupil, the normal to the mirror 

 through the dot is the visual axis of the eye— a determinate line. 

 A right-angled prism is fixed to the board near the eye in such a 

 position that the eye sees the image of its own cornea in profile 

 by reflection, first at the prism, and then at the mirror. A ver- 

 tical line is drawn with black sealing-wax on the surface of the 

 prism next the eye, and the board is moved towards or from the 

 eye till this line appears as a tangent to the front of the cornea, 

 while the dot still is seen to cover the centre of the image of the 

 pupil. The only way in which the position of the board can 

 now vary with respect to the eye is by turning round the line of 

 vision as an axis, and this is prevented by the board being laid 

 on a horizontal platform carried by the teeth. I( now the eye 

 is brought into two different positions and the board moved on 

 the platform, so as to be always in the same position relative to 

 the eye, we have to find the centre about which the board might 

 have turned so as to get from one position to the other. For 

 this purpose two holes are made in the platform, and a needle 

 thrust through the holes is made to prick a card fastened to the 

 upper board. We thus obtain two pairs of points, A B for the 

 first position, and a b for the second. The ordinary rule for 

 determining the centre of motion is to draw lines bisecting jI a 

 and B h at right angles. The iaterscction of these is the centre 

 of motion. This construction fails when the centre of motion is 

 in or near the line A B, for then the two lines coincide. In this 

 case we may produce A B and a b till they meet, and draw a line 

 bisecting the angle externally. This line will pass through the 

 centre of motion as well as the other two, and M'hen they coin- 

 cide it intersects them at right angles. 

 Manchester 



Literary and Philosophical Society, Feb. 2.- -Mr. 

 Alfred Brothers, F. R.A.S., president of the section, in the 

 chair. — Results of meteorological observations taken at Lang- 

 dale, Dimbula, Ceylon, in the year 1S73, by Mr. Edward 

 Heells ; communicated by Mr. Joseph Baxendeli, F. K. A.S. 



Feb. 9. — Mr. Edward Schunck, F. R.S., president, in the 

 chair. — A method of finding the axes of an ellipse when two 

 conjugate diameters are given, by Mr. J. B. Millar, B. E. ; com- 

 municated by Prof. O. Reynolds. — Mr. E. W. Binney, F. R.S., 

 V. P., presented to the .Society a bust of the late James Wol- 

 fenden, of Ilollinwood, one of the most noted mathematicians of 

 the Lancashire school, who was born on the 22nd June, 1 754, 

 and died on the 29lh March, 1S41. 

 Dublin 



Royal Irish Academy, Jan. 11.— William Stokes, F.R.S., 

 president, in the chair. — The Secretary read a paper, by Mr. J. 

 Rhys, of Rhyl, on Ogham inscriptions. — Dr. Edmund Davy 

 read a paper on some newly observed properties possessed by 

 certain salts of fulminic acid. — Dr. Doberck, astronomer at Col. 

 Cooper's observatory, Markree, County Shgo, read a paper on 

 the Comet I. of 1845. 



Jan. 25.-— William Stokes, F.R.S., president, in the chair.-- 

 The Rev. Edward M'Clure read a paper on Irish popular names. 

 — Samuel Ferguson, LL.D., vice-president, read a paper on an 

 Ogham inscription at MuUagh, Co. Cavan ; also notices of the 

 Monataggart Ogham texts, from the Bishop of Limerick, 

 Whitley Stokes, LL.D., and Rev. R. D. Haigh.— Rev. Dr. 

 Reeves, vice-president, read a paper on the MS. in Marsh's 

 Library called the " Codex Kilkennensis." — Mr. II. W. Mackin- 

 tosh read a paper on the structure of the spines in the Diadema- 

 tid.-e. — Dr. A. Macalister read a paper on a few points in the 

 cranial osteology of Bradypus gularis ;" also a paper on the 

 anatomy of insectivorous Edentates, Part I. 

 Paris 



Acadeiny of Sciences, Feb. 15.— M. M. Fremy in the 

 chair. — The following papers were read : — New researches on 

 the mode of intervention of electro-capillary forces in the 

 phenomena of nutrition, by M. Eecquerel. — On the depth 

 and the superposition of magnetic layers in steel, by M. J. 

 Jamin. — M. Faye made some remarks on M. Jamin's paper, 

 — M. de Lesseps then made a communication relative to the 

 question of unification of the tonnoge of vessels ; after which 



M. Dupuy de Lome made some remarks on the same. — Experi- 

 ments on the absorption by the root of plants of the red juice of 

 Phytolacca decandra, by M. H. Baillon. These experiments are 

 in continuance of those made by Biot, De la Baisse, and Unger. 

 — On the defective notes of string instruments, by M. A. Dien. 

 This paper has special reference to the violin and violoncello, 

 and treats of those harsh and buzzing notes commonly known by 

 musicians as the wolf. — On the presence and the formation of 

 '■ibrioiics in the pus from abscesses, by M. Albert Bergeron ; 

 researches made at the Charite Hospital, in Paris, in pursuance 

 of. M. Goselin's paper read at the meeting of Jan. 11 (Nature, 

 vol. xi., page 240). — On a dissemination apparatus of Gicj^arina 

 and StyhrhyncJins, and a remarkable phase of sporulation in the 

 latter genus, by M. A. Schneider. — A memoir, by M. Ch. An- 

 toine, on some mechanical properties of saturated steam. — A 

 memoir, by M. A. Picard, on a new method to establish the 

 equations of elasticity of solid bodies. — A note by M. M. 

 Girard on the influence of cold temperatures upon Phyl- 

 loxera, showing that thsse insects are not much affected by 

 cold, and that it is useless to count upon their destruction by 

 cold winters. — A note, by M. A. Demoget, on various improve- 

 ments made upon Holtz's machine; these improvements ensure 

 its perfect action even in the dampest weather.— The Secretary 

 then read the following telegram received from M . Bouquet de 

 la Grye, the chief of the expedition sent to Campbell to observe 

 the Transit of Venus; — "Venus seen before ingress only; 

 no contacts; all well." It is dated from San Francisco. — • 

 A note, by M. E. Riviere, on the quaternary deposits, supe- 

 rior to the ossiferous cavern of Nice, known as the superior 

 cavern of Cuvier. The author cons'ders that the red inferior 

 deposit in the caverns of Mont-du-Chateau, of Nice, must be 

 regarded as the true ossiferous breccia, and that the superior 

 deposits were formed by accumulations of detrital matter. The 

 animals whose bones originate from this deposit were contempo- 

 rary to the human beings of which Cuvier described a jawbone. 

 — On a case of dimorphism in the genus of Graminece, by M. 

 E. Fournier. — On the discovery of true Batrachia in primary 

 strata, by M. A. Gaudry. — On the discovery of a fossil species 

 of Bovidae, probably Bubahis aiitijuus, at Djelfa, Algeria, by 

 M. P. Gervais. The same gentleman then showed some repro- 

 ductions of flint implements found in the caves of Ousid.in, near 

 Tlemcen, Algeria. — A note by M. Chapelat, relative to a lai-ge 

 bolide supposed to have been observed on the evening of Feb. 

 10. It was afterwards found that the supposed meteor was only 

 the edge of a cloud brilliantly illuminated by the sun, which 

 had already set. — A note, by M. de la Haye, on atmospheric 

 electricity and the presence of hydrogen in the atmosphere. 



BOOKS AND PAMPHLETS RECEIVED 



American. — Papers on Natural Erosion by Sand in the Western Terri- 

 tories ; The Recency of certain Volcanoes of the Western United States ; 

 and the advantages of the Colorado Plateau Region as a Field for Geological 

 Study: G. K iGilbert (American Association for the Advancement of 

 Science). — Report of the State lioard of Education on the proposed Survey 

 of the Common\ve«llh>(Boston, Wright and Potter). -Monthly Report ol the 

 Department of Agriculture, Nov. and Dec. 1S74 (Washington, U.S.) 



CONTENTS Page 



A German Manual OF Scientific Inou'RV 321 



The Sandwich Islands (//7//( /.Y/M^ra//o;M) 322 



OUH Book Shelf :— 



Dr. ILiUs" Sun and Earth" 324 



Letters to the Editor : — 



On the Building up of the Tone in the "Gamba" Organ-pipe.— 



Dr. Hermann Smith 325 



Periodicity of Rainfall— C. Meldrum 327 



Ice-Caves —Rev. T. G. BoNNEV .327 



Tlie Morse Code— Prof. W. F. Barrett 328 



Tlie Micrographic Dictionary— Pollen Grains.— W. G. S.mith . . 32S 

 OcR Astronomical Column : — 



f • and f- Reticuli 3^8 



The Binary Star « Cassiopea; 32S 



The Binary Star a Ceatauri 328 



Red Stars 328 



Encke's Comet 328 



Bearing of Meteorological Records on a Supposed Change of 



Ci-imate in Scotland. By Alexander Buchan 329 



Natural Phenomena in South America. By J. Munko {With 



Illustyaiiojis) .... 329 



The Birmingham College of Science 331 



Notes 332 



Preliminary Inquiry into the Existence of Elements in the 



Sun NOT I'REViou.sLY traced. By J. N. Lockvee, F.R.S. ... 334 



Scientific Serials 33^ 



Societies and Academies 337 



Books and Pamphlets Received 340 



